My freshman year in college (engineering school, no less) I was taking a humanities course, final quarter, and the professor told us that we had to go and see a play at New Voices, the amateur festival put on by the college. New Voices, at the time #6, was a week long opportunity for the students to write, direct, produce and star in original plays. I had a great time.
Something about the experience stuck with me, and I started writing plays. No training, and I’m not a theatre major either. But I did have plays in NV#7, 9, 10 and 11.
So that brings me back to the link above, to a classroom resource ebook entitled Move Over Shakespeare and appears to be for teaching students how to write a play. In general I don’t love Shakespeare being lumped in with every other playwright in the known universe, but I can live with it.