I know that windows Movie Maker is a fairly easy to use video editing program. I don't know it it will let you put still images in your movie though, plus i think it only maves avi movies or wmf. If you have Win XP you should have this. You might be able to download it from microsoft. Ulead VideoStudio is a program that will do what you want. there is a 30 day trial version of it here:
http://www.ulead.com/vs/trial.htm . As far as completely free programs, i don't know of any off the top of my head, but if you got to
www.tucows.com, they have a huge listing of shareware/freeware software.
hope this helps