The Phantom Professor is offering an online writing workshop. (HT: Michael Spencer, BHT) She knows the topic well.
However, she mentions screenwriting. I think there's one really big secret to successful screenwriting: the three-act play. If you don't have three acts, don't bother submitting your script to a talent agent or producer. Maybe it's brilliant. There are plenty of successful non-three-act screenplays, but they were all done independent of major Hollywood studios.
My suggestion is to go find a book on playwrights and start there. Learn everything you can about storytelling for theater and become intimate with the three-act structure. It won't give you many new ideas, but it will help you understand what people in power are looking for.