Research Tutorials and Handouts: Citation & Bibliographic Management

Provides assistance with in-text citations, the references list, and formatting papers in APA style. Covers a variety of resource types such as emails, blogs, movies, sound recordings, data sets, etc.

Free for MLA. Recommended by instructors and students for undergraduate use.

Zotero is "a free, easy-to-use Firefox extension to help you collect, manage, cite, and share your research sources. It lives right where you do your work—in the web browser itself." Intuitive interface and lots of documentation on their website.