There are so many and this reminds me that I need to pick up a few books myself. Anyhow, look for anything by Jorge Cervantes, Ed Rosenthal, Robert Connell Clarke or Jack Herer. There are many more but these are probably the most well known, they are also mostly older books and I'm sure there are some newer stuff that is more pertinent to growers these days. With the amount of knowledge most of us have discovered, learned and have access to via the internet, none of the books will likely be mind blowing or loaded with lots of new info you didn't know about before or anything like that but it's definitely cool in my opinion to have hard copies of information to reference without getting on a computer. My wife wants to scan and digitize all my magazines and stuff that I keep for future possible referencing so she can throw them all out but I won't let her.