There are 2 books that are considered as being the best.
The first one just came out a little while ago and is written by the person that runs NERD (New England Reptile Distributor's), Kevin McCurley. NERD is one of the "biggest" ball python breeders, have an excellent website and an extensive collection. Having never dealt with them myself, all I can objectively say about them is that they have one of the best reputations out there. Check them out at www.newenglandreptile.com/ . There is a link on the front page for the book. I don't own a copy but people speak very highly of it.
The second one is a little older, it is called "The Ball Python Manual" . And until Kevin's book came out, it was considered the best, so you should still consider it as being an excellent reference. Check it out at www.amazon.com/gp/product/1882770285/sr=8-1/qid=1139519004/ref=pd_bbs_1/104-8974148-1557561?_encoding=UTF8 . If that link doesn't work, just search for "ball python manual" in Amazon, or even google. The book is by Phillip de Vosjoli et al.
Get as many books as you can afford, they all offer differing and interesting advice.
Joel
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0.1 Ball Python
0.1 Okeetee Corn Snake
1.0 Leopard Gecko