tga, tiff, iff (there called a lossless compression file type) or bmp ( 100% uncompressed) are much better quallaty then jpegs . we were told in uni never render to jpegs for final stuff as they get really compressed. i also find bmp are very large files but by far the best quilaty as there is no compression on them.

In premire when you import a file there is a check box on the bottom saying image sequance.

I personally use iff when rendering which shake, digital fusion, photoshop (with pluggin) and after effects take but not premire. Then change them if i need to.

I also never render avi`s from maya, images all the way baby