We found 1 Reddit comments about Harlow and Harrar's Textbook of Dendrology. Here are the top ones, ranked by their Reddit score.
I can only think of books that work on a national level.
Textbook of Dendrology. (Kind of expensive)
USFS Silvics Manual (Free, but not exactly for ID'ing)
These are basically my bible for tree species ID.
Is it for general interest or for a class? Either way, I'd suggest finding a local book from your region. If you don't already know how, I'd suggest learning the jargon of leaf shape, etc. and how to use a dichotomous key.
I'm assuming this is for native species. If you're in an urban environment, it can be almost impossible to identify species because of non-native ornamentals.