EDIT: I would like to delete this instructable but cannot since it was part of a contest (30 seconds to explain something).
This video has enough information inside to teach someone about the absolute basics about an internal combustion engine. It includes lots of engine vocab and a quick walkthough (more like a sprint) of the ICE process. I built this engine model for the purpose of teaching myself more about ICE engines, it took a long time! Hopefully i spoke clearly enough so that my speed does not interfere with your brains sucking up this important information!. : )