Find a pattern rated "easy" and go from there. Visit any fabric manufacturer website, they have many free patterns you can download. I find teaching with a pattern is very simple. The pattern tells them what size to cut the pieces, all that's left for you to do is roam the room and help as they have questions. On the first day show them rotary cutting how-tos, and explain a few terms, such as "fat quarters" or "scant 1/4"" and go from there!