Big buttons, only modal dialogs. Stay away from open options and give people a list to select from. The average person recalls more from recognition than memory. Stay away from anything that would require recalling abstract information.
Provide feedback, again idiots will keep hitting things unless they get some kind of instant feedback.
I could talk to a friend of mine about it. she has a degree in designing training programs, technical writing and industrial design. I'm sure she'll know a bit. I'll see if I can get some good reference sources.