I picked up The Portable Film School by D.B. Gilles
at a local bookstore because it looked like an easy-to-read, beginner's overview of lessons taught in film school. I enjoyed reading it, but it turned out to be a lot less about film school than about writing screenplays. While there is a chapter dedicated (at least, at a high level) to the nuts and bolts of shooting and editing a film, the majority of the book is about writing. I suppose the message from the author is that without a solid screenplay, you can't shoot a decent film.
If you are looking for details about the filmmaking process, you should probably look elsewhere, but if you want a quick read that delivers a high-level overview of filmmaking with an in-depth tutorial on writing screenplays, then this is the book for you.