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.
Zotero is a free "research assistant" that allows you to "collect, organize, cite, and share" your sources right from a bookmark in your web browser. It will sync data in the cloud and across multiple devices, allowing you to work on your research no matter where you are.
EndNote is a paid option that costs about $250 to download. Some researchers find that the more-accurate citations, greater array of supported citation styles, and better interpretation of journal abbreviations justify the price.