This should get you started

http://ball-pythons.net/forums/showt...ius)-Caresheet

Generally it is easier to obtain a glass tank to house them in. These can be a bit of a pain to keep humidity up as well as provide a secure environment. Needless to say that a 20g wide with a secure top would suffice nicely. I do believe that racks are the more preferred method of keeping BPs. But this usually pertains to people keep more then just one and are also used widely by breeders. Since you are looking to keep multiple snakes a rack may suite you better in the long run.

Greg