It is easy to buy from Taobao if you are based outside China. it is apparently possible to sell too, but you would need to do this through an agent especially if you are using English as your business language. There are people who seem to be agents for Taobao; you could have a look at MZ Hosting, for example. They would obviously charge a commission, and as they seem to be quite new it's hard to know whether it's a good idea to use them or not, but it does look as if an agent of some kind is the way to start. They claim to offer translation, design and a lot of other services, so if the commission is not too much it may be worth contacting them to ask a few questions.

You could also contact the Taobao site yourself and ask for information about finding and using an agent there.