Stanford Encyclopedia of Philosophy
The industry-standard encyclopedia for philosophy. The articles are great, though not always easy reading, and include lots of bibliography and further references for investigation. A good place to get ideas for term papers and start your research!

American Philosophical Association
Our professional society. Many useful links.

David Chalmers' Site
David Chalmers' prize-winning website with many, many wonderful links to everything from abstruse papers on metaphysics and philosophy of mind to sites on weird psychological abnormalities to philosophical humour sites.

A Field Guide to Philosophy of Mind
Excellent site for discussions of current topics in philosophy of mind--as far as it goes. The site is still under construction: some of the topics still don't have entries up and some of the entries don't have bibliographies. But it provides an overview of topics in philosophy of mind. And what's there is good.