Evaluating the sources you find is a crucial step in the process of scholarly research. The questions you ask about books, periodical articles, or multimedia sources are similar whether you're looking at a citation to the item or have the item in hand.
How to Critically Analyze Information Sources.
Lists some of the critical questions you should ask when you consider the appropriateness of a particular book, article, media resource, or Web site for your research.
Distinguishing Scholarly from Non-Scholarly Periodicals: A Checklist of Criteria.
Shows how to evaluate periodicals by looking at their format, intended audience, and appearance.
Evaluating Web Resources
Lists ways to analyze the Web sites you find.
Turabian, Kate L. A Manual for Writers of Term Papers, Theses, and Dissertations. 5th ed. Chicago: U Chicago P, 1987. (Uris and Olin Reference PE 1478 T92 1987) A newly revised and expanded version by B. Honigsblum, of Kate Turabian's standard guide for student writers. online version
MLA Style (MLA's web site)
Provides some FAQ's; however, this site does not provide the full style manual online.
MLA Handbook for Writers of Research Papers (6th ed.)
Olin and Uris Libraries Z253 .M68 2003 (located at the Reference Desks) APA Citation Style
Once research involves lots of sources and lots of pdfs, most people find using citation management/pdf organizing software saves time and energy.