Ball pythons are one of the easiest snakes when it comes to providing a proper enclosure. They do not climb, they do not move much and they do not need special lighting. What you do have to provide for them however, is a good deal of room, (remember, this is snake that is four or five feet long and built very thick) a nice spot to hide, (they will very likely sleep in that spot all during the day and only come out at night) warmth, and high humidity.
Habitat: The exact amount of room required depends directly on the age and size of your snake. For the most part, a 10-gallon aquarium will work very well for a baby python, and a 40-gallon breeder works for an adult. The "breeder" shape (low and wide) is ideal since a long aquarium would be too thin to allow the snake to turn around quickly, and a tall aquarium would have a lot of room that the snake would not actually use (remember, they do not climb).
A hiding spot is important in order that your snake not feel constantly exposed and vulnerable. Ideally, you should provide something that is just big enough for your snake to curl up inside. You want to go for smaller rather than larger as much as possible since the snake will actually prefer to have his body pressed right up against the sides. A nice half-log or wooden hide box also provides a rough surface for your snake rub against when it's time for him or her to shed.
Heating & Humidity: Whatever you use as an enclosure, you should create a range of temperatures that goes from around 80 degrees up to around 90. The easiest way to create this range is to put a heat source (a heat lamp, an under tank heating pad, but NOT a heat rock) on one side of the cage and let the other side be cooler. If you use a bright light for a heat source, make sure it is always turned off at night (a cycle of 12 hours on and then 12 hours off typically works well) since these are nocturnal snakes, constant bright light overhead is both stressful and confusing for them, and can result in poor feeding and grumpiness. Also, it's best not to guess at the temperature; get at least one thermometer for the tank (they're cheap) so that you know for sure your snake is in optimal conditions. Otherwise if your snake starts to have a problem (loss of appetite, problems shedding) you can more easily rule out things such as inadequate heating.
Humidity is important since in their natural habitat (Jungles of Western Africa) they have adapted to breathing humid air and having a high ambient humidity (80% or more) at all times. If kept in too dry an an environment, they can become dehydrated and have difficulty shedding. The easiest ways to keep the humidity high are to have a large water bowl (large enough for your snake to soak in if he feels the need) under the heat source, and to periodically spray the substrate with a little water. A good mulch or bark type substrate will soak up the water and then let it evaporate into the air of the tank, allowing a steady supply of humid air.
Feeding: When it comes time to feed your snake, it's better to feed pre-killed or frozen and thawed rodents. Admittedly, seeing your snake hunt a live mouse or rat is more exciting, but there is a risk (a small one, but still a real risk) that if your snake does not eat his food, his food could turn around and injure him badly. If your snake does not initially show interest in prey that is not running around, try heating up his frozen dinner in chicken broth. If you must feed live (either for personal preference or because your snake will not accept pre-killed prey) then be sure to supervise all feeding and never leave a rodent in with your snake for more than and hour at the most.
Start off young snakes on one mouse every week, then as they grow (around 2 feet or so) start adding mice to the weekly meal. Make it two or three for a while. Then once the snake gets around three or three and a half feet, you can start trying rats. Certain snakes will not accept rats at first and if you find yourself in this situation, you can try the chicken broth trick from above, or when you buy your rat, have Wild Side employee through some mouse bedding over your rat. By the time you feed your snake rats, his appetite will likely only make him want to eat every other week or so. It's also normal for snakes to skip a few meals from time to time. A healthy snake can go moths without eating and ball pythons are particularly sooner to fasting. If you're worried (which should only happen after a few skipped meals) first try making the enclosure hotter by a few degrees. Then try some novel prey items to stimulate interest (frozen chicks are available online and are often taken by otherwise completely disinterested snakes). Of course, you know your snake the best and if he stops feeding and there are any changes in behavior or you're just not OK with letting it go for a while, do not hesitate to bring your snake and / or a sample of his poop (gross, but sometimes important) to your vet to check for parasites or illness.
This info should definitely help you get started. As always, we encourage you to ask lots of questions and do your own research. The more you know about your pet, the better you can take care of it and the more you'll enjoy it.