Recommended Books:

Critical Encounters in High School English: Teaching Literary Theory to Adolescents by Deborah Appleman
Critical Theory Today: A User-Friendly Guide by Lois Tyson


Websites:

http://bcs.bedfordstmartins.com/virtualit/poetry/critical.html - This site has definitions and essays on various critical approaches including feminist criticism, the new historicism, psychoanalytic criticism, reader-response criticism, structuralism, marxist criticism, the new criticism, formalism, and post-colonial criticism.

http://www.kristisiegel.com/theory.htm - This site lists various critical/theoretical approaches with definitions, key terms, and suggested websites and books.