Mendeley is a free reference manager and academic social network that can help you organize your research, collaborate with others online, and discover the latest research.
Videos about Mendeley: http://www.mendeley.com/videos-tutorials/
Zotero is a free bibliographic software that you can use to download and organize bibliographic citations and to create a bibliographes. It automatically downloads references from indexes and databases. Use it to organize references into different files so that they can be easily retrieved for various papers and projects.
You must use Firefox.
To use Zotero go to www.Zotero.org and follow the instructions. You may want to choose Zotero 2.0 (beta) because it stores your data on the Zotero site, allowing you to access your information from different computers. The original version stores everything on your computer.
Check out the Fondren Libguide on Research Management, which covers Zotero, Papers, and Mendeley in more depth.