Zotero is a free, simple plug-in (for Firefox) or a standalone program (with browser extensions to Google Chrome and Safari) that collects, stores and organizes references for books, journal articles, websites and other materials that you've collected and then automatically converts those references into a properly formatted bibliography. It is fairly easy to use, reliable, and well-documented. Zotero can:
Alongside tracking literature citations, Zotero stores downloaded or links to Acrobat pdf files or any other types of files on your computer.
See the complete guide for more detailed information. See the Tisch Library Workshops webpage for a schedule of workshops.