Does anyone have any recommendations for identification books that are specific to California? Books on birds, plants, and fungus are what I’m mostly looking for but things outside of that are also helpful. I’m also interested in buying an encyclopedia (about California wildlife) for myself and didn’t really know where to start… One with a lot of pictures would be nice since I like to use them as art references on occasion.
Welcome to the forum! For plants there’s Jepson (in ebook format elsewhere but not for free that I’ve seen). And this probably is less of what you’re looking for, but here’s some for marine bivalves, terrestrial gastropods, and cave fauna. The last 2 are more checklists than true ID books, but still helpful. The underlying IDs come from much denser, older texts that either aren’t restricted to California or are highly restricted in the groups they cover.
Mushrooms of the Redwood Coast by Christian Schwarz and Noah Siegel is pretty great and both authors are active on iNat. (Full disclosure, Christian is a friend of mine, but it’s a great book)
I know you didn’t metion herps, but if you’re in southern California (or visit it often), I really like Lizards of the American Southwest - so many great photos, and good instructions for observing lizards ethically.
As @thomaseverest says, the Jepson Manual is probably the best guide for practically any plant you’ll find in California. I bought Trees and Shrubs of California a while ago, and I carry it around with me whenever I’m hiking (especially in unfamiliar forests or shrub land) because it’s small enough to carry. However, the number and variety of species is rather lacking, and it’s by no means as comprehensive as the Jepson. It focuses solely on trees and shrubs as the name suggests, and even then it’s missing many trees and shrubs that you may encounter frequently.
I have been enjoying their Field Guide to California Insects, which doesn’t attempt to cover every single insect (or it would be a whole bookshelf) but provide a good representative sample. Although they did accidentally list Chrysididae as being part of Chalcidoidea, which sent me on an internet search to find out whether the taxonomy had been reorganized recently (No, I think it was just a missing heading)!
I don’t have a Jepson manual, I should remember that I want one. I have Belzer’s Roadside Plants of Southern California which is a thin book that nonetheless covers the vast majority of plants I see hiking in Los Angeles county; it’s a great introductory book in terms of covering the most common plants without being overwhelming. Of course, only of any value in the range it covers :)
By the way calflora.org is fantastic once you get the hang of their search!
I have the Audubon Field Guide to California but I honestly don’t find it that valuable as someone who actually lives in California. I think it’s better for someone preparing for a vacation here. So that’s a non-rec from me (for California residents).
My mushroom book is Arora’s All that the Rain Promises and More but honestly given the drought I haven’t really had occasion to use it since I bought it. I’m more used to using MykoWeb https://www.mykoweb.com/ but I can’t take it into the field unless there’s cell service…
Depending on where in CA you are there might be very local books, covering a region or even just a county. I like Flora of the Santa Ana River and Environs, and Wildflowers of Orange County and the Santa Ana Mountains. Both authors of that second book are on iNat so it is fun when I see them making IDs.
As well as the great suggestions so far, I’ve lots of mileage out of my western Peterson guidebooks. I’d also like to give a shout out to the amazing Natural History of Orange County website, at http://nathistoc.bio.uci.edu/. I have no connection to it but it was my go-to place for starting to learn the Orange County species when I first visited California. It’s a simple interface with a wealth of information and images.