Here’s some pages I like to use and follow:
The Futon Critic: A great resource for all things television, regularly updated and full of great information. There’s an alphabetical listing of TV shows, mostly from the 21st century, that you can check to see if your show is canceled or not.
TV By the Numbers: An always up-to-date, informative site about show and network ratings. If you want to keep up with your favorite shows to see if they are in danger of being canceled or not, this is the place to be.
Television Without Pity: One of the web’s leading TV sites for years, they have hilarious episode recaps and all of the information you could ever want regarding TV.