Don't forget to check out Skeptics Guide to the Universe, only the best damned thing on the interwebby thing. Pulled me back from some dark, castaneda-related, youthful transgressions and set me back in the right direction!
You can find them at www.theskepticsguide.org, cannot recommend them enough!
(aint it funny how, for an atheist, I seem to use a lot of religious terminology? Amazing to think how much that memetic force has permeated through time. I chuckle to think of the religious people destined to find my page through mistaken search hits...)