Skeptics Guide to the Universe
The Skeptic's Dictionary
Provides alphabetical links to various topics that can serve as a jumping off point for research. Left hand menu also provides themes and categories to begin looking in in order to narrow down a topic. Some entries are topics in pseudoscience, while others are meant as evidence against a particular pseudoscientific belief.
CSI (Committee for Skeptical Inquiry)
Maintains a webpage of links to different topics scientists are frequently skeptical about. Their stated mission is to "promote scientific inquiry, critical investigation, and the use of reason in examining controversial and extraordinary claims".