dont go with avi, its crap.
Batch render your your animation as targa files.
Then use videomach (very easy to use) to turn those targa files into either an avi or mpeg.
mike mckinley has a great tutorial on rendering, thats how i learnt.
As for the sound. (Assuming its all synched with what you need in maya).
You dont even need a complicated program like After Effects (unless of course you're good with AE). Just download any program. I have Ulead video editor AND after effects, and i STILL use Ulead if its just for sound,...purely because its so quick and simple.
So here you are...
step 1) Follow the great mike mckinleys tutorial
step 2) Use video mach, import your Targa files. (like i said very easy...follow Mike). When completed you will have a smooth video in either avi or mpeg.
Step 3) With ULead or any video editing program,..import both your sound AND your newly rendered video into it, and create a video file or render it out in that program or do whatever it requires to output the final version (vid and sound)
hope this helps
those who succeed are only the failures that never gave up.