This is not so much a course in writing screenplays as a series of commentaries on the process and the problems. If you want to learn how to do it, well first read something like Syd Fields "Screenwriting" and Robert McKee's "Story". There are lots of other books out there as well. Ray Frensham's "Teach Yourself Screenwriting" is worth a look in, if for no other reason than he came on my course and borrowed some of my notes to help write the book.
I used to teach all this stuff long before Syd Fields wrote any books about it and probably I invented a lot of the stuff people quote now as supposedly expert opinion. Personally I turned to teaching it in order to make money when I couldn't sell any scripts! So I always felt it was the illiterate leading the dumb, or something. However, in teaching it, I learned more than any of my students.
Here's lesson Number One: Writing is messy! And the end result only looks coherent and sharp after a lot of work has taken place ordering and structuring the erratic workings of your imagination.
Eventually there will be five articles here... but I haven't written the other two yet. Mercifully, they will be short. Or is that hopefully? One or the other...