Purpose: "To summarize what is known about some issue or field on the basis of research evidence, and/or what lines of argument there are in relation to that issue or field." (from The Sage Encyclopedia of Social Science Research Methods).
Where:
You probably can't be exhaustive, so selectivity is key.
Try to cite the most relevant and important articles. (Look at information in Google Scholar on how often the article has been cited).
Tracing citations both backward and forward is a key element: look at both an article's bibliography, and the articles citing that article.
- Chronological
- Thematic
- Methodological
- Within any such organizational scheme, you might further divide the works reviewed into categories (e.g., those in support of a particular argument and those against).
- Methods/Standards: How did you select your sources (e.g., did you only use peer-reviewed journals)? How did you decide to present your information (e.g., you present your information thematically, to address one question at a time)?
- Questions for Further Research: Do you see unanswered questions in the field?