The Literature Review is part of a research paper in which the author provides a historical account of the research on the topic, along with recent developments. While other parts of an paper may cite non-research articles, the Literature Review only cites research articles.
It is also an important way for you to become familiar with the specifics of your topic, including specialized language used, key researchers, and which journals are publishing on the topic.
Research articles are primary sources. Secondary Sources include books or trade papers citing original research, while General Sources include newspapers, magazines, blogs, and Wikipedia.
What steps do I take?
You'll want to use at least two databases as you begin your searching for research articles. These tips will help you as you go.
Pay attention to the language being used and incorporate the terms into your search. For instance, are they referring to a group as "children" or "youth"?
Don't read the full article at first. Start with the Abstract, then move to the Conclusion, then to Methodology, and finally the Literature Review and full paper.
Keep track of the articles you read in a Google Doc, Word Doc, or even a citation management tool like Zotero (video tutorial). The last thing you want is to recall a paper you read but not be able to find it again!
After you read the article, write your own brief summary of the article, including who the researchers are, what demographic or other community they are studying, what data they collected, and what their results concluded. Finally, add a sentence or two on how the article relates to your topic area and the other articles you've read.
As you find relevant articles, pay attention to how the researchers write their own Literature Review section and use that as a model.
Also, pay attention to what other research the authors are citing, and which articles are citing them (video tutorial on this).