Help plz - Reducing Video file size?

Problem:
I have avi and mov videos I want to upload. So that someone else can download them.
They were taken with my camera(s) and are way to big in filesize (5 minutes = 300 mb or something).

Does anybody know a small, easy program to compress them? As simple as 'open video' - 'choose codec/compression' - 'save' - 'done!'?
Preferable with codec inside already or with codec I could use as well?
Also: Free to use program please, if possible.

Thanks!