Librarians are here to help!
Research in theater and dance can be important for production, criticism, or history and might involve finding reviews of a performance, criticism of a text of a play or a choreograper's work, or information on a historic period in which a production is set.
This guide to resources for theater and dance lists some key research tools, but is far from complete; please don't hesitate to ask a librarian for other suggestions.
Modern Dance - http://www.flickr.com/photos/kevineddy/2449103652/
Tragedy and Comedy - http://www.flickr.com/photos/franglais/163090032/