This site is NO LONGER being maintained for the "ALL NEW" site that talks about the new iMovie 11 please visit TheUnofficialiMovieFAQ.com
If you need immediate help, I would highly suggest you make use of the Apple forums. This site has a wealth of information but the Apple site provides a bit more of interactivity, a broader range of skills, and people. I would start in the forums myself. Go to the iMovie forum and use the search funtionality.
Another good source of information: I think many people just do not know how easy it is to use the Apple knowledge base search ability. Quick answers are here to too, just use key works like "imovie and export"
You can e-mail me a question (Dan.at.DanSlagle.com) and you will, eventually, get a response. But, you must understand I literally get 100's of e-mails a day so you may not get a response for a few days and odds are if you search the Apple forums that the answer is there. Usually with a link back to this site