A literature review is a systematic survey of the scholarly literature published on a given topic. Rather than providing a new research insight, a literature review lays the groundwork for an in-depth research project analyzing previous research. Type of documents surveyed will vary depending on the field, but include:
The purpose of the literature review remains the same regardless of the research method you use. It tests your research question against what already is known about your subject. Your review will:
Jeffrey W. Knopf goes into terrific detail and description about doing a literature review - what it includes, what it doesn't include, how to approach your search, and how to arrange the scholarship when writing the review. It is a short, but great read, if you would like more detail:
Jeffrey W. Knopf. (Jan 2006). "Doing a Literature Review," PS: Political Science and Politics, Vol. 39, No. 1: pp. 127-132.