I had to do the same thing last semester. I began teaching the parents news articles/discussion and after a few weeks I was politely told that they were extremely bored. Afterwards, I began teaching them basic conversation skills (time, introductions, weather, etc) and they found it very useful. Also, try to use realia from home such as photos, the contents of your wallet (i.e. driver's license, costco cards, currency, etc), and food. I actually made them tacos (I'm from California) and they absolutely loved it.
As for the teachers, I taught them English idioms using powerpoint/photos. They found it extrememly comical to translate and dissect an idiom in the literal sense (i.e. "ball and chain", "get off my back" and my favorite, "going postal"). Also, I taught a lot about culture. For example, they had no idea about Bigfoot, the Lochness monster, prom night, the process of getting a driver's license, etc.
Teaching the parents and teachers can be extremely fun..don't stress out about it too much.