I have been looking for books to help me better understand and ID insects any suggestions?
Where in the world do you live?
Your profile mentions Virginia, so this recommendation is based on an assumption of North America.
My go-to is Borror and Delong’s Introduction to the Study of Insects. It’s focused on North American taxa, and is often used as the required text in introductory entomology courses at the college level.
If you want to focus on aquatic insects, An Introduction to the Aquatic Insects of North America by Merritt, Cummins, and Berg is fantastic (but can be expensive and is somewhat redundant to the Borror and Delong text if this isn’t your focus). It includes a lot of info about sampling and ecology of the various taxa too.
Both texts include keys to at least the family level for adults and immature forms, with many illustrations.
I also recommend familiarizing yourself with bugguide.net. There are useful descriptors included in many taxa pages, and each taxon has a section devoted to additional resources, many of which are available online.
Assuming you dont want a field guide for a specific family, in which case you need to share what that is.
I believe older issues of Borror and DeLong can be downloaded as pdf’s.