Writers Guild of America, West
Writers Guild of America, East
Write Brain
Word Player
Screenplay.com (Movie Magic Screenwriter, our top recommendation for writing scripts)
Final Draft
Script Ware
Redbird Studios (Writers in general)
Directors Guild of America
Film Festival Index (slow, but detailed)
FilmFestivals.com
Screen Actors Guild
Actors Equity Association
Actors Equity Casting Call
American Federation of Radio and Television Artists
[AFTRA has their own GREAT set of links!]
The Actor's Source
Now Casting [first-rate online casting service]
Acting Depot
The Actor Site
Breakdown Services
CastNet
On Stage
PlayBill
Pro Artists Group
The Right Cast
Internet Movie Database (free)
Baseline
Film Finders
Hollywood Creative Directory
Showbiz Data
Studio System
Daily Variety
The Hollywood Reporter
Backstage/Backstage West