Reddit reviews The Art of Fiction: A Guide for Writers and Readers

Ayn Rand had some really great tips about overcoming writers block: http://www.amazon.com/The-Art-Fiction-Writers-Readers/dp/0452281547

Well, solidify the idea you want to convey first, then, make a map or something so you can travel through all those characters you like to create, place them, on the stories, fiction, non-fiction, western, drama, etc, etc,
some things that may help you:
http://www.amazon.com/The-Art-Fiction-Writers-Readers/dp/0452281547

http://www.amazon.com/On-Becoming-Novelist-John-Gardner-ebook/dp/B00AB7NYZU

http://www.amazon.com/The-Writers-Journey-Structure-Edition/dp/193290736X

Best book for screenwriting IMO: John Yorke's 'Into The Woods'

And best book for writing (which gives valuable, but indirect lessons in screenwriting) IMO: Ayn Rand 'The Art of Fiction'

Hope this helps!