This link will lead you to: workshops and the comparisons page for RefWorks, EndNote & Zotero. This is also the main page for the Libguide for Refworks.
P.S. From Audrey Welber (email@example.com ) 2/16/12 re: Zotero
works with other browsers now: http://www.zotero.org/blog/zotero-3-0-is-here/
Note that all/any of these services make the mechanics, the formatting, of paper writing easier. They can be more closely associated -- more compatible with -- different groups of databases, like ProQuest with RefWorks, and Thomson-Reuters with EndNote; however, all references can be imported and exported between/among the different programs.
"RefWorks -- an online research management, writing and collaboration tool -- is designed to help researchers easily gather, manage, store and share all types of information, as well as generate citations and bibliographies." (Refworks homepage)
RefWorks Help -- Tutorials
"Millions of researchers, scholarly writers, students, and librarians use EndNote to search online bibliographic databases, organize their references, images and PDFs in any language, and create bibliographies and figure lists instantly." (From the EndNote ProductInfo page)
EndNote Web basics online tutorials There are many free classes and webinars offered by Thomson Reuters, as well as Princeton. Those on the web are aimed at the many different versions.
"Zotero [zoh-TAIR-oh] is a free, easy-to-use tool to help you collect, organize, cite, and share your research sources. It lives right where you do your work—in the web browser itself." (from their homepage)
Zotero 3.0 is available -- as of January 31, 2012, it is now available for Mac, Windows and Linux.