Admin is right, Windows Movie Maker does a good job of compression, and you can select what you specifically want as far as size. I would keep it below 70MB if at all possible when rendering. It will take a while though, so patience is a virtue here.
Another trick that some people do is "sharpen" the image using WMM or Vegas, or whatever they use to edit the film using the built in effects. They use the sharpen effect/filter. I personally don't do this, but I know a lot who do.
Also, make sure when filming to remove any window messages. They sometimes detract from the video presentation. Keep it clean
