http://stumblerum.com/blog/writing-mistakes
http://owl.english.purdue.edu/owl/resource/557/01/:
http://www.mla.org/: The people who wrote the book on Research Papers.
http://citationmachine.net/: Makes almost all your citation needs easy.
http://ec.hku.hk/writing_turbocharger/proofing/grammarc.htm: If you need help using your word processor to check for errors.
http://www.lausd.k12.ca.us/lausd/resources/Literary.Terms.2.html: A good index of literary terms.
http://www.tnellen.com/cybereng/lit_terms/: Another index of literary terms