this guide +
my guideshould be all you need to make the video entry and upload it
changing the container/codec can be quite a bit more involved, and I'd suggest you read
the new eadfag to get a grasp on how to do it. Technical, yes...but loaded with good information. The tools most people use for encoding video are virtualdub (or virtualdubmod) and/or meGUI or Zarx264GUI