The Skeptic's Dictionary is a wonderful resource for all sentient individuals: 'A Collection of Strange Beliefs, Amusing Deceptions, and Dangerous Delusions (and how to think critically about them)'. It's where I send people when they start telling me nonsense.
It is also a jolly good read: try the entry for natural, for example. And some entries, like the entry for IQ and race, verge on the profound.
There is a print edition, but the extensive internal and external site linkage makes reading the collection online a particular joy. While The Skeptic's Dictionary has been referred to before on MeFi, the link made the site out to be a cornucopia of Urban legend-style oddities, like Snopes. Which I thought was a shame: not dissing Snopes, but the Skeptic's Dictionary delivers a firm grounding in critical thinking as well.