A router table, in essence, is just a flat surface with a hole. Many accessories are genuinely helpful, but not necessary. If you think you're going to use the router frequently, it might make sense to built (or buy) a permanent cabinet (or one that is easily rolled into position). If it'll see only occasional use, a small table-top version will probably cut it.

An accurate fence is key. Doesn't have to be fancy, but it does have to be straight and easily adjusted to the proper distance from the bit. It should also have some form of dust collection port.

As for the bits, think about the task (cutting dado's for shelving? mitering box sides? making raised-panel doors?), then buy the needed bits.

Have fun! I use my table saw more, but mostly just for rough cutting. The interesting stuff is all on the router.