If you have never bought a snake online, then there are a few things you should know, before you actually take the plunge, and buying one.
First, it is important that you trust the dealer you buy from. There are so many breeders who sell their snakes online, and just picking out a website, and sending them your money, is not the way to go. If you find a breeder, and look at the photos they have on their site, and you think you want to buy one of their snakes, then the next thing you need to do, is find out a few things about the dealer.
Will they be there for you, if something is wrong with your snake? How much do they charge for shipping? Do they guarantee live arrival? Some breeders can be very friendly before the sale, and then not so friendly after the sale.
A good way to find out the general reputation of a breeder, is to visit snake and reptile forums. If someone has had a bad experience, it has a tendency to get out there where people can see.