There is no shadow of a doubt in my mind that the script is (by far) the most important asset you can have in the film industry today. If you have no money, no experience, and no connections but you have a 120-page masterpiece on a PDF, then you have something that Hollywood (and the world) wants and is willing to pay a lot of money for.
You will, therefore, have an easier time getting agents, producers, and directors to read it and help you get it made. Life is made easier by an amazing script. This is why I encourage people to focus their energies on gaining as much theoretical and practical knowledge in writing, above all else. Technical knowledge in the art of filmmaking is all over the place, but the ability to write a great story isn’t as common. So, do yourself a favor – as an independent filmmaker – work every day to enhance your skill. It’ll be the thing that makes the biggest difference between winning and losing in this industry, and the one thing that’ll get you noticed quicker.
Here is a list of my all-time favorite screenwriting books (not in any particular order)
Screenplay by Syd Field
The Art of Dramatic Writing by Lajos Egri
Making a Good Script Great – Linda Seger
Story by Robert McKee
The Writer’s Journey by Christopher Vogler
Into the Woods by John Yorke
The Anatomy of Story by John Truby
How to Write a Movie in 21 Days by Viki King
Essentials of Screenwriting by Richard Walter
The 21st Century Screenplay by Linda Aronson
Save the Cat by Blake Snyder
150 Screenwriting Challenges by Eric Heisserer
Screenwriting Tips, You Hack by Xander Bennett
Plots and Characters by Millard Kaufman.
Adventures in the Screen Trade by William Goldman
How to Write Dazzling Dialogue by James Scott Bell
Dialogue by Robert Mckee
Creating Character Arcs by K.M. Weiland
Super Structure by James Scott Bell