Zotero is a free bibliographic tool that allows you to store and organize your research. Here are some features of Zotero:
Download info is available at http://www.zotero.org
Find helpful information at http://www.zotero.org/support/ including hints on adding items and organizing your library, generating bibliographies, syncing materials, and helpful tips and tricks.
Here are some Zotero introductory screencasts to get you started!