windows special effects

What’s a good (freeware) program for windows that I can use to add special effects to movies?
The special effects in question are overlays of pictures, captions, and stuff like that. I would also like it to save in a format with which I can post on YouTube.
Thanks in advance.
windows movie maker is included in all windows installations. it’s pretty good for freeware. you can also try adobe premiere elements. there’s a trial version at http://www.adobe.com/downloads/
WIndows movie maker special effects Test