Encyclopedias (use at least one of these two sources):

Groliers Encyclopedia
        Short background articles on a variety of Shakespeare-related subjects

Oxford Reference Online
        Short dictionary and encyclopedic articles related to Shakespeare

Web Resources (if you use a Web page, it must be from the following list, not one found through a search engine):

Search "Shakespeare" in Librarians Index to the Internet

Shakespeare Links (from the Internet Public Library)