Your instructor may require you to use MLA style citations. The info on this page will answer the majority of your MLA questions. If you still have questions about MLA style, you may need to consult the MLA handbook, which is available in the library.
Purdue's Online Writing Lab has terrific instructions on how to set up your paper in MLA Format and how to cite sources in MLA Style.
The ARC Guide will answer most of your MLA questions and has lots of examples of how to cite sources.