For quick guidelines for applying MLA style, consult a concise and free resource available through the World Wide Web: The Owl at Purdue
Or, the NYU Bibliographic and Footnote Style Guide
For official information on how to cite your sources, there are two resources:
Take notes, organize your research, import citations from electronic databases and catalogs, format your references in dozens of standard styles (MLA, APA, etc.) for bibliographies; insert footnotes and endnotes directly into your papers.
NYU libraries offer a number of citation management tools to our users and the ones listed below are some of the more popular tools available. However, in order to make the right choice of citation management tool for your research, take a look at the comparision chart: Comparing Citation Management Tools