Determine the nature and goals of the research for which you're writing the proposal. Determine why the literature you're writing about is relevant to your research.
Present the reader with a summary of the research and information that has already been done on the subject. Evaluate this research critically by pointing out the why the research is relevant and useful but also what it lacks. Provide enough information to show a reader that you've done a thorough job of looking through the available literature dealing with the topic but do not make it exhaustive.
Present the outstanding questions that must be answered and the information gaps that must be filled in about the topic to show how your research will contribute to advancing the knowledge of this field.