http://www.videohelp.com/
or
http://www.doom9.org/

will tell you everything you need to know about video conversions, and have the software you need. (on Videohelp click "tools" on the top bar to see the software, then pick out of the redish menu the type of software, make sure it is listed as freeware)

If you join either of their forums, dont mention piracy or anything to do with it, they are in denial about what they are doing, and will ban you.