If it's an Intro to Theatre kind of a class, you might want to try to give them a little taste of everything. Starts with the basics: SETS, COSTUMES, LIGHTING, SOUND, DIRECTING, PLAYWRITING, STAGE MANAGEMENT, ACTING (pardon me if I left anything out) With every project, have them learn sort of the essence of what these sections mean. Final project idea... have some write a 10 minute play and then get kids to act it out while someone directs them and other kids contribute to costumes/lighting/sets. I had a really good intro to poetry class that operated under the fundamentals of (Let's analyze this piece of work for 30 mins, and then the next 30 mins lets mimic the style they use and see how it works for you). Applying that to an intro to theater class would be something like (This is what a lighting designer does, let's see how applicable it would be to our fictional production of Oklahoma). While you teach the kids what a section is about, you can use show examples and expose them to that too..