Zotero and Zotero Bib
Zotero, a free, open source citation management tool will take the process of collecting and organizing citations, incorporating them into your paper, and creating a bibliography or works cited page to the next level.
It's worth the small investment of time to learn Zotero. A good guide, produced by Harvard librarians, is available here: http://guides.library.harvard.edu/zotero.
Upcoming classes online (or in person, if you're close to Cambridge) are open for registration here.
DON'T HAVE TIME TO LEARN ZOTERO RIGHT NOW?
ZoteroBib, a free citation generator, may be the answer for your E-100 paper. It lets you build a bibliography instantly from any computer or device, without creating an account or installing any software. Some of its handy features are described on this page.