Need Basic Help With Video, Please :)

This will get into Internet and Web Design eventualy, but for now it's just basic stuff.

I have some web space where I've been storing audio clips (for linking to) and things are going good so far. Now, I have some video I'd like to put up there. What it is, is a video recording of sort of a "practice session" I did several years ago, actually back at my parent's house...

Which is why I'm here about this instead of going with trial and error. It's a very important file, and a large one at that-

I need to greatly reduce the size of an .AVI file. Mom ripped the file into 640x480 screen res, and it's about 4 minutes long, so we're looking at 251MB! I need this thing reduced down to about 10MB... the screen size could go down to 240x180 and still be good, but I'd like to retain as much audio quality as possible.... and, uh... I've never even tried to edit any kind of video file... and have no clue how to change settings in windows media player... Thanks!