A concise and fabulous guide to writing a literature review; gives clear examples of how to use a synthesis matrix (a literature review grid like we used in class) to pull your sources together. From Florida International University.
Tools to help
Using a chart like this one (easily made in Google Drive or Microsoft Excel) can help you organize your sources.
Bubbl.us is a concept-mapping tool; you may prefer this visual way of organizing and connecting themes in the literature (you can concept-map on paper or in other mind-mapping tools, as well).