More than likely, you'll want After Effects. Premiere is primarily for video editing....you can add transitions, work with sound, and some graphics, titling, etc. If you plan on doing a lot of compositing (ie. rendering out separate objects or passes from Maya), adding photoshop elements, rotoscoping, matting, etc. etc., I'd say go with AE. I like to think of it as a kind of photoshop for video as you build your compositions layer but layer. If you want more of an idea of how it works, download the demo and check out Rage's video tuts on Compositing in the Freebie section. That'll give you more of a sense of what you need.
"Terminat Bora Diem, Terminal Auctor opus."