Carl Sagan's Baloney Detection Kit. IMO this should be required reading for every user of the internet. Read it, understand it, and install and run it on the software between the ears. :)
The following are suggested as tools for testing arguments and detecting fallacious or fraudulent arguments:
Wherever possible there must be independent confirmation of the facts
Encourage substantive debate on the evidence by knowledgeable proponents of all points of view.
Arguments from authority carry little weight (in science there are no "authorities").
Spin more than one hypothesis - don't simply run with the first idea that caught your fancy.
Try not to get overly attached to a hypothesis just because it's yours.
Quantify, wherever possible.
If there is a chain of argument every link in the chain must work.
"Occam's razor" - if there are two hypothesis that explain the data equally well choose the simpler.
... more...
http://www1.tpgi.com.au/users/tps-seti/baloney.html