google is often your best friend for techie stuff
"easy" avi to mpeg converter, brought back this:
http://doeasier.org/avi-converter/
I can't say if it's good or not as haven't used it myself.
Are you wanting to watch the converted files on a DVD player? if so, the first link although lengthy will do it a treat, if you just want them in another format to play on your pc, try the easy-avi converter..