Are you using a PC or a Mac?
If you're using a PC, then you probably have Microsoft Movie Maker installed, which is pretty good for a free piece of software and very straightforward to use. There are plenty of add-ons and upgrades available for it, too.
iMovie is the Mac equivalent, and if you have a new(ish) Mac then it should come pre-installed. If not, I think you may have to purchase it from them.
Avid used to offer a program called FreeDV, but it's no longer available. You may still be able to download it from a Torrent site, though. I've never used it, but I do use Avid Xpress Pro and Media Composer and the interface looks very similar. If it's only a fraction as powerful as those programs, then it should be good!
Edit: Forgot to ask... what camera/model are you using?