There's several books that are good, it all depends on what you need.

There's the simple, inexpensive beginner care book:
http://lllreptile.com/store/catalog/...python-manual/
This is great for basic care information and generalized information, which is what beginners need most.

There's the somewhat pricier mid-range book, which is excellent for those beginning to breed and those who need help learning genetics:
http://lllreptile.com/store/catalog/...l-python-book/
This book is very thorough and covers a lot of topics in depth that a starter book may not. It also has some excellent chapters on punnett squares, which is very helpful for those starting to breed designer mutations.

Last but not least is the most recent book by the Barkers, called Pythons of the World, volume II, which is about ball pythons. It's probably one of the most expensive books about snakes out there, but the information in it is invaluable. It very well could be considered a snake textbook, and the care, husbandry, and general information in it can be applied to a wide range of snake species. It is, without question, one of my top 5 most cherished books in my personal collection, and I recommend it highly for anyone truly serious about ball pythons, or about snakes in general. Unfortunately, our store doesn't carry it, but I believe you can order it by calling VPI directly.

Hope that helps!

-Jen