Really the only choice you'd need to decide is whether to start on a PvP or PvE server, unless you really want to RP then go to an RP server.
I'd say go with any server that shows "Recommended" There are a lot of established servers out there, but some are steadily declining in population (Antheron) while others are steadily increasing (Uldaman).
I'm sure theres some other guys on the boards that can tell you a few good servers to start on that have established economies, good bg que times etc.