Essential Books on Screenwriting
I just added a new post on ScreenplayLists.com: Essential Books on Screenwriting. The first book on the list is an obvious one: Syd Field's "Screenplay."
You may not be enlightened by Syd Field's classic, but you won't be disappointed, either. If you've written screenplays for a while, you probably already own this.
Check out the full article for more reviews of essential screenwriting books.