GHS - Worth the paper it's not printed on? Identifying and avoiding fake news: What is it and what can you do about it?

A product of the Annenberg Public Policy Center, this site is terrific for checking up on political claims.

Similar to Snopes but tighter in scope, Hoax-Slayer focuses on email hoaxes, identity theft scams and spam.

A professional networking website where you can look up the authors of articles and books to see if they're credible.

The Pulitzer Prize-winning Politifact researches the claims of politicians and checks their accuracy.

One of the oldest debunking sites on the Internet, Snopes.com focuses on urban legends, news stories and memes. the also cite their sources at the end of each debunking.

While focused primarily on political facts, it covers specific claims in-depth and with plenty of cross-referencing.

A reverse image search; enter an image's URL to see it's history. TinEye can be easily accessed through the Google extension RevEye.