Best advice I can share with you since you don't have the snake yet is to of course do your research on the species, then find a website for this show and do your research on the breeders that will be there. Not all breeders are the same and you should try to buy from only the best, most reputable breeders out there. Makes for a better transaction and usually a healthier snake.
Also, please have a look at caging and housing options you'll see our members post about. Most of the stuff your average chain pet store will sell you and tell you is absolutely necessary for ball pythons is both crap and overpriced crap at that (or it's completely useless for this species of snake). Please do NOT buy an electric heat rock - they can be deadly but pet stores really tend to push those on the unsuspecting.
Once you know your housing choices, check in here for advice on where to get your supplies to get the best bang for your buck. You'll want to set up the snake's home a few days to a week in advance so you know it's all dialled in nicely.
Oh and don't forget to find out all the info on the snake when you buy it at the show. It's so easy to get overexcited and forget to ask things like when it was hatched, what it eats (make sure you've already researched local rodent suppliers), what method of feeding it's used to, etc. All that stuff is important so that you can help your new little scaley buddy settle in easier. :)
