These are some of the best locations on the net for the aspiring screenwriter to get information from. I highly recommend "Done Deal" so that you can get an idea out of what is selling. The following websites are free and/or have free memberships.

A good pay site to join is Variety magazine's
variety.com. This will keep you up to date with daily news in the entertainment industry.

Script Sales
This is the home of Done Deal. Contains all daily script sales as well as plenty of industry resources.

Film Stew
One of the best places to get noticed. Has one of the largest contact sections I've seen. Upload your resume and bio here.

Trigger Street
Kevin Spacey's Trigger Street Productions. Great place for young filmmakers to begin.

Movie Cliches
If you want to avoid them then read this comprehensive list. It will also give you a good laugh.

Internet Movie Database
Find out information on any in the film business including every movie ever made.

Ain't It Cool News
Very large site that contains spoilers and other information on upcoming movies and television shows.