What is the final output? If you are making a DVD, I would make a standard 720X480 timeline. When you drag the clips in there it will letterbox with the black bars on top and bottom. This will make sure it plays back fine on whatever TV or projector it plays back on.
If you know it will play back on a wide screen TV you can edit in anamorphic (just be sure that when you go to DVD Studio Pro that you make sure the wide screen option is checked in the timeline there). Just make sure you test it before you play it for the class.
Hope that helps,
Jeff