Save the Cat! The Last Book on Screenwriting You'll Ever Need by Blake SnyderI just finished Save the Cat! and Mr. Snyder mentioned that having a board to pin story elements to helps identify where the holes are. He suggests to tack as much to the board as you can, so you can delve into writing with confidence...you know where to start and where it's going.
Teach Yourself Screenwriting by Raymond Frensham
How to Write a Damn Good Novel by James Frey
Writing Dialogue by Tom Chiarella
He also urges screenwriters to write a logline before they get started. This is a VERY short summary (28 words or less) of your story. The Cracking Yarns blog was very helpful in this area and contains lots of other useful information too.
The Board - details
I've written and revised my first chapter book and will be sending it out to agents/editors that visited the last SCBWI Western WA conference last April and are accepting solicitations from attendees. While that's in the cooker, I've already started my second book and wanted to try using the board as Mr. Snyder suggested.
I have it all tacked down...now I need to start writing. Once I get cracking on that, then I'll know if spending the time writing, tacking, moving, and eliminating index cards was worth it. So far, I'd say it was a worthwhile exercise.