Online Literary Criticism Collection - http://www.ipl.org/ref/litcrit/
(From the Internet Public Library)

The Cambridge History of English and American Literature -  http://www.bartleby.com/cambridge/

American Authors on the Web - http://lang.nagoya-u.ac.jp/~matsuoka/AmeLit.html

Literary Resources on the Net -  http://andromeda.rutgers.edu/~jlynch/Lit/

Literary Index - http://www.galenet.galegroup.com/servlet/LitIndex