Online sources are (unfortunately,) fragmented. Its hard to find things written in layman’s terms in online sources that are written in a comprehensive manner - usually things will be focused on one genus or family, or they’re regional. Even if the names are out of date when it comes to scientific names (and they all are, no matter how recently they’ve been published) books are still my go to because they tend to represent more comprehensive data.
That said, I’ll endeavor here to give a few links that may be useful, and at least outline some of the most obvious groups that you’re likely to come across. This still won’t be comprehensive, but it might help a little bit.
As far as websites, my go to general site is mushroomexpert.com - though this is mostly focused on the US and beyond that, the eastern US, mostly because the site’s author is based in my area.
For boletes (at least, American boletes,) the bolete filter (https://boletes.wpamushroomclub.org/) is a fairly invaluable resource; I’m sure there’s good resources for old world boletes but I’m less familiar with them
Amanitataceae.org is the site that aggregates info on Amanita mushrooms, though it lacks a user friendly key
For stuff in the UK, this site - https://www.wildfooduk.com/mushroom-guide/ - seems to be a fairly reliable one, though they mostly seem to focus on edibles and poisonous mushrooms - you’ll find that most ID information online is focused on these things.
https://www.shroomery.org/ aggregates information for mushrooms containing psilocybin, so there you’ll find information about Psilocybin, and to a lesser extent Gymnopilu, Pluteus, paenaeolus, and some others - though its not fully an ID-focused site, of course.
I won’t skip over it either, there are things like mushroom clubs and facebook groups - I’m sure you have one locally - that are very useful to join to see what is common in your area and what gets IDed. Just join a local one, and lurk, and see what the people who know what they’re talking about say things are.
And if you really want to get into the weeds and look at more scientific papers, I like to reference Mycobank.org (great site to look up when a species was described and in what paper) Indexfungorum (Lists species names + what their synonyms are) and Mycomap (aggregate site for DNA sequencing and distributing reports that pulls from inat, mushroom observer, gen bank, etc)
All that said, don’t underestimate the value of local identification books. If you learn what you can about those, dig into some more general books.
And with that out of the way, I will attempt to at least cover some basic, easily identifiable groups/genuses - for the most part, I’ll skip species here and stick with more general categories, since those should be relevant for most of the world.
Ascomycetes & Basidiomycetes
So this is the most basic split you’re going to find below fungi.
Ascomycetes is really where all the weirdos go. And I’m certainly not an expert on this group, far from it, but this is where you’ll put all the weirds. Yeasts, molds, cordyceps fungi, lichens, tiny little jelly discs and logs and just a few really obvious macrofungi like Morels and Peziza. most of the stuff here is stuff that is just going to be straight up impossible to ID without microscopy, but I’ll note a few in a moment. Outside of those, I’m not going to talk about this group that much because I’m personally not great at it, and there really doesn’t exist a good source talking about all of it
Genuses of note include
-Morchella - morels. one of the most sought after edibles. Just google this one,trust me, you know what a morel looks like.
-Gyromitra - false morels. They mostly looked like brains on sticks
-Helvella - elfin saddles. They look like… well, saddles on sticks
-Peziza - big cup fungi, for the most part.
Basidiomycetes are where most of our more charismatic macrofungi live, so if its recognizable as a cap-and-stem mushroom its safe to put it here. I’ll go so far to say if it is, you’re safe to skip all the way down to Agaricomycetes - I’ll go out on a limb and say almost everything you look at it and say ‘that’s a mushroom!’ is going to fit in here, outside of a few rare exceptions. Jellies and such will probably end up in Tremellomycetes but tbh computer vision can at least get you to the ballpark on most of these (if it throws a species, just jump a few levels to say, family, and you’re probably good.)
Agaricomycetes and orders/subclasses of note (not touching on everything, just ones you’ll encounter often
Agaricomycetidae Most of what you’ll find under here goes either in Boletales or Agaricales - I’ll touch on these two more in a bit.
Auriculariales - Here lives all the weird jelly fungus that don’t belong in Tremmelomycetes. Here you’ll find
-Auricularia - wood ears. They’re mostly brown, they kind of look like ears. The common name really fits here
-Exidia - Dark brown and usually look like someone took a bunch of gum drops and smashed them together on a log/branch/twig/what have you
-Pseudohydum - they’re jelly fungus with teeth on the fertile surface. They’re neat and feel weird and neat when you rub them
-Ductifera - your white jelly bois
Cantharellales - This is a famous group and contains some even laymen will recognize, including
-Cantharellus/Craterellus - these are your chantarelles and trumpets. They come in a range of colors, usually black or red or orange, lack true gills and instead have a smooth to wrinkled fertile service, and are generally prized as edibles. The biggest difference between the genuses is craterellus are generally hollow while cantharellus are not.
-Clavulina - these are a group of coral fungi and can be extremely hard to get anywhere close to species. If it looks like a coral, you can put it here - and don’t worry the coral people will tell you you’re probably wrong, but they’re usually nice about it.
-Hydnum - these are the hedgehog mushrooms. They have teeth on the fertile surface, though they are far from the only species that has teeth. Important thing to note is, afaik, you’ll find these growing out of the ground.
Hymenochaetales - This has a lot of crusts and weirdo shelves. Not a great group for me, though a shootout to the genus Trichaptum (aka violet toothed mushrooms,) which really seems to be the majority observed genus for this group
Polyporales - these are where most of your shelf fungi are going to live. A few genuses of note
-Fomitopsis - mostly conk fungi, plus the birch polypore Fomitopsis betulina (which is a pretty distinct white polypore that grows out of birches and has an inrolled, overhanging margin.) Most of these suck to try to get past species unless you’re really in to them
-Ischnoderma - the resinous polypores. These guys generally are dark, not-shiny polypores with white pores and a white margin. They start out soft and get harder in age, but when young they’re squishy (Also, they’re delicious if you can get the soft bits when they’re young, as an aside)
Meripilus - black-staining polypores. These are gray-to-tan-to-brown polypores that tend to grow in a rosette habit and bruise black very quickly when touched or damaged.
Cerioporus/Polyporus - probably the most common species here is C. squamosus AKA dryad’s saddle/pheasant back, which is a white pored mushroom with a brown & tan feathery-looking upper surface that can get quite large and smells like watermelon rind. There are a few other species in this group too, brown polypores on stems with white pores is a good indication
-Laetiporus - Chicken of the woods. Big, orange and yellow shelf fungi that are pretty unmistakable. There’s a few in this genus that don’t quite match but if you see a giant orange pored mushroom, it belongs here. CV almost always gets this right
Fomes - hoof fungus. These are more brown polypores that grow on trees. Really they’re kind of hard to separate from a few other genusus, usually I just throw these in Polyporales and call it a day.
Sparrassis - cauliflower mushrooms. They looks like a big white coral growth or a head of cauliflower; choice edible and CV is pretty decent at it
Ganoderma - contains both the laquered bracket fungi (subgenus reishi), which are shiny topped white pored red and brown and yellow brackets, along with things like artist conks, which are matte but you can draw pictures on their pore surface, which is neat.
Lentinus - some of these are gilled, some of these are not - its a weird group, they look kind of like funnels with either gills or big pores on the bottom.
-Trametes - turkey tails. Little fuzzy shelves with bands of color and white pore surfaces. Extremely cosmopoliton
-Grifola - Hen of the woods. Looks like a hen butt, or a pile of leaves next to a tree. Grifola frondosa is a highly sought after forageable
Russulales - a group you’ll want to know. contains some gills, some teeth, and some pores, I’ll shout out a few
-Russula - hugely cosmopoliton and notoriously difficult genus to identify to species. These guys are usually brightly colored, in reds and yellows and greens, and usually have cream to white gills. They’re usually brittle, may be spicy, and may bruise or blacket. Genus is usually very easy with these but species is incredibly difficult, especially in america
-Lactarius/Lactifluus - These are also in russulaceae. They look like russula, but are more varied in colors and cap texture, and will bleed a milky latex when cut.
-Hericium - lions-man fungi, they look like pom poms or cascading waterfalls of teeth. Usually white, may be pale pink depending on conditions
-Stereum - false-turkey tails. They look like turkey tails but are thinner and more fragile and lack a proper pore surface
-Artomyces - Crowned-tipped coral, a fraigle coral fungis that grows out of wood and is relatively easy to ID
Sebacinales Probably the most notable genus is Sebacina, the false corals. Its another one that looks like a coral, these have less defined branching then most.
Theleporales This contains a few weird looking corals and a few more toothed groups like Hydnellum and Sarcodon, but I don’t see them that much personally
Phallomycetidae A few groups of note here
-Geastrales - these guys look like a puffball wearing a star-shapped collar
-Gomphales - these contain more corals like the genus Ramaria along with a chantarelle mimic genus called Gomphus that kind of looks like brown-to-purple chants but definitely aren’t.
-Phalleles - these are your stink horns. Smelly, usually grow from an egg from the ground, ten to be white to red to brown. Most of your classic stinkhorns are going to go in Phallus (the head has a skirt) or Mutinus (the head doesn’t have a skirt)
Boletales & Agaricales
We’re finally at the two groups that most people care about. I’ll start with Boletales because its by far the smaller group; in it, you will find cap-and stem mushrooms with pores (though there are a few gills mushrooms in here)
-Suillus - They looks like boletes but aren’t actually in boletaceae, they’re in their own family. These are the suillus, sticky capped sometimes hard to ID yellow to brown pored mushrooms that may or may not have a veil. If it has a veil and a ring and its a bolete, it belongs here
-Leccinum/lecinnelum - scaber-stalks. These are boletes with… well, scabered stalks. Kind of dotted and extremely hard to ID to species
Boletus - this used to be the umbrella genus and is slowly getting pared down to contain on the boletes closely related to the Porcini/Boletus edulis. edulis-group boletes come in a range of colors, but key id features include an olive-yellow/brown spore print, white reticularion on the stem, and generally pleasant flavors.
Neoboletus - this is the genus most red-pored blue-staining boletes that lack reticulation end up in, though there are a few species hanging out in Boletus still. This is an incredibly messy group in need of a proper paper to sort it out so don’t be afraid just to stick stuff at Neoboletus and call it a day.
Rubroboletus - has a few different species but the biggest note is lots of red and yellow and sometimes white coloration, and lots of fine red reticulation on the stem
-Aureoporus - usually have brownish to wine colored caps/stems with bright-to-dull yellow pore surface. These are small boletes, and there are a few oddballs in here.
-Tylopilus - bitter boletes (though not all of them.) white pore surface that ages pink with a pink spore print, these comes in shades of brown, pink, purple, or black and flavor can be very important when it comes to actually getting these to species
-Phylloporus - oops this one has gills? But its a bolete! Small red-to-brown mushrooms with highlighter yellow gills that look like a bolete from the top
-Paxillus - Squatty brown mushrooms with an inrolled cap margin and gills that really don’t look like they should belong here.
And now on to Agaricales; this is going to be FAR from comprehensive but I’m going to try to cover the most common groups that you have at least a modicum of hope of identifying
-Amanita - we know them, we love them. This group is huge and contains a ton of mushrooms, but they share a few features, including free gills, a mycorrhizal habit, volvas/universal veil (a sac/egg that they emerge from, through it doesn’t always remain saccate,) along with a partial veil in most species.
-Pluteus - Deer mushrooms. Free gills, wood-rotting, mostly brown though with a few brightly colored members, with a pinkish-brown spore print
- Agaricus - these are where your store bought button mushrooms live. Lots of species that are hard to ID, but they share a partial veil and a brown spore print and usually start out with pink or white gills
-Cortinatius- rustgills. These have a very webby partial veil called a cortina and drop a rusty brown spore print. They range in color from dull brown to bright purple to red and orange, and can have either a dry or viscid top
-Inocybaceae - Fibercaps. These need a lot of sorting, but are mostly little brown mushrooms with fibrous caps that split longitudinally very easily. Also very hard to get to genus, let alone species.
-Clitocybe/clitopilus - funnels. Mostly white mushrooms with gills that run down the stem and grow from the ground. Lack a veil
-Volvopluteus/volvariella - Rosegills. White mushrooms that do have a volva, but unlike amanita they have a pink spore print and their gills turn pink as they age
-Coprinellus/Coprinopsis - inky caps. If you’re unsure on these you can stick them in Psathyrellaceae and call it good because they’ve been split up a lot. Most have a unique spore delivery method where the gills dissolve into black goo
-Coprinus - another inky cap group, though this one does not go in Psathyrellaceae. These are a little more stout than the little ink caps, and the most recognizable species is Coprinus compatus, the shaggy mane mushroom
- Hygrocybe/Gliophorus/Cuphophyllus - waxcaps. Hygrocybe are usually very brightly colored (reds and oranges) and can be dry or sticky, gliphorus are brown to blue to green and are basically always viscid, and Cuphophyllus are more modestly colored waxcaps and come in whites, creams, browns, etc. White spore prints, generally small, growing on the forest floor. Some species may stain black
-Psilocybe/Deconica - Used to be grouped together but this group was split into the Psychoactive Psilocybe and the non-psychoactive deconica. Little brown mushrooms that grow out of wood or poop, have a purplish-brown spore print, and may or may not stain blue
-Psathyrella/Candelleomyces - Brittlestems. THey’re brittle, they’re small, lots of LBMs here. Honestly these I usually just stick at family level unless I know the species
-Leucocoprinus/Leucoagaricus - Lots of white mushrooms here with a partial veil but NO volva, there are a few other colors you might find; some might stain red, some have scaled caps, some have bulbous bases - not my best group
-Chlorophyllum/Macrolepiota - parasols - contains one nasty poisonous boi that has a green spore print (chlorophyllum molybdites) and several good edibles that have white. Scaled to shaggy tops in various shades of white and brown and have a persistent ring that does not look like a skirt
-Lepista -white to purple to pink to brown clitocyboid mushrooms with a pinkish buff spore print - Lepista nuda is the big species here, though there’s a few others. Can look a lot like purple cortinarius at first glance
-Armillaria/desarmillaria - honey fungus - wood rotting super common parastic fungi with a white spore print that tend to grow in rosettes or huge flushes
-Mycena - Bonnets - little wood rotting fungi that tend to grow on clusters on logs or from leaf litter, often brown or white but sometimes brightly colored (though some grow from dirt too, because this is a huge variable group)
-Entoloma -Pinkgills - a hugely variable genus that can grown from multiple substrates, have multiple cap textures, and come in a dissying array of colors - but they have a pink spore print
-Pleurotus - oyster mushrooms - white gills that run down the stem, they grow from wood and are pretty identifiable
I’m going to stop here for now - there’s definitely more groups, and I’ll probably add a few more later, but most of this is off of the top of my head and I need to take a small pause. Agaricales is absolutely HUGE and contains most of the gills fungi and can also be the hardest group to key out so… yeah.
Feel free to add more, and I may add more later if I’m feeling up to it.
EDIT: Thought of a few more to add
Lycoperdon/apioperon/calvatia - Puffballs. Lycoperdon are white and usually have spines or spikes or hairy bits on the outside, apioperdon are little brown puffballs that grow on wood, calvatia are the big ones. Yes, these are in agaricales.
Scleroderma - earthballs/pigskin puffball. brown, pitted, thick skin and a dark spore mass inside if you slice them in half.