A literature review displays what has been published on a particular subject/topic by recognized researchers. Usually, it is part of the introduction to a research report, essay, thesis or dissertation.
A literature review can be a simple summary of the sources, but more often, it is organized with a summary and synthesis. A summary is a recap of the important information of the source; a synthesis is a re-organization of that information.
Search for the most recent articles that deal with your topic; many of them will summarize the prior literature in the area, saving you valuable time. Remember to attribute the source even if you paraphrase.
Literature reviews can be overwhelming. You can't find everything. Just find the literature that gets discussed the most or is most relevant to your topic.
The goal of a literature review is to show an understanding of the bigger picture; it puts research and recommendations in context of others working in the field.