A Writer's Resource

Name of site: ComingSoon.net
Type of link: Movie trivia
Warnings: n/a
Explanation of link: A simpler database than IMDb, but very up-to-date when it comes to the latest news releases from the studios, and the scheduled release dates for movies. 

Name of site: IMDb.com
Type of link: Movie trivia
Warnings: n/a
Explanation of link: The biggest and best reference for movies online.  Want to know when a movie came out, or what movies were playing in a certain year?  Check it here.  It's user-driven, but generally accurate.

Name of site: Notstarring.com
Type of link: Movie trivia
Warnings: n/a
Explanation of link: A site that reports on rumors and confirmed facts about who might have been in movies and who actually got the part.  Great fun to look at, and a nice resource if you wanted to "mix up" movies in an AU story.