Syd Field is considered the absolute authority on all things screenplay. During his life, he was considered “the guru of all screenwriters” according to CNN. He was on faculty at USC in the prestigious Master’s of Professional Writing Program, and also taught at UCLA, UC Berkley, AFI, Stanford, and Harvard. Field spoke around the world and has been a consultant to many film studios (such as 20th Century Fox, Universal, Disney, etc.) and several governments.
Syd Field has penned several books that are basically screenwriting bibles, if I may. Screenplay: The Foundations of Screenwriting, The Screenwriters Workbook, and The Screenwriter’s Problem Solver, are just a few examples of books every screenwriter, professional or armature must own; and, while you’re at it, pick up his whole library.