Zotero: The Tri-College Libraries recommend Zotero, a free tool that can format your bibliography, keep your citations organized, and even save your articles in the cloud so you can access them later from the library, home, or a cafe. See the Tri-College Guide to Zotero for more details.
EndNote Basic: The Tri-Colleges provide free access to EndNote Basic. See the Tri-College Guide to EndNote Basic for more details.
Any librarian will be happy to give you a tour or a few pointers of the software.