I really like Soma's organic growing book called "Organic Marijuana Soma Style - The pleasures of Cultivating Connoisseur Cannabis" by Soma. It keeps things quite simple and gives a really good summary on how to successful pull off a 100% organic soil grow, and in my opinion organic soil is the way to go!
I have also read Ed's book as well as Jorge's and they are both very informative too. If you have the money I would get all three books! All three growers have different styles and opinions on different topics so I think it's a good idea to learn as much as you can and then find out what works best for you.
Knowledge is power!