This movie will show you how to get a good web version of your movies. When you do this, iMovie '09 makes .m4v version that usually opens in iTunes, ready for syncing with an iPod. If it's to be used on the web, it's a good idea to change that to .mp4 or .mov so that it will open in a browser (and not download to iTunes). The movie shows you how.
You can see a larger version here.