NoodleBib is an online tool that prompts you for information about your source (title, author, etc.), then generates a citation in the style you specify (MLA, APA, or Chicago).
Osterlin Library has created three video tutorials that will get you started using NoodleBib: "Getting to NoodleBib," "Creating Citations with NoodleBib," and "Printing and Saving Citations in NoodleBib."
Purdue OWL: MLA Formatting and Style Guide: This detailed guide from Purdue covers all the basics of MLA style.
MLA Citation Style (from Cornell University Library): A simple overview of MLA works cited pages and in-text citations.
MLA Handbook FAQ: Frequently Asked Questions about using the newest edition of the MLA Handbook.