Marijuana Botany: The Propagation and Breeding of Distinctive Cannabis I've never read it but it looks interesting: http://books.google.com/books?id=_a...&ct=title&cad=one-book-with-thumbnail#PPP1,M1
There are many books and videos out there that of course can be found on the net but if you are going to go buy some, anything from good ol' george cervantase or ed rosenthal should be the most benificial.