Below you will find three commonly used style manuals that show how to cite a variety of sources, including documents from the Internet:
Publication Manual of the American Psychological Association.
6th ed. Washington, DC: APA, 2010. (Ref BF76.7 .P83 2010)
This book presents APA style requirements and provides examples for all types of information sources.
APA Style (examples)
The MLA Handbook for Writers of Research Papers.
7th ed. New York : Modern Language Association of America, 2009.
(Ref LB2369 .G53 2009)
MLA Style (examples)
A Manual for Writers of Research Papers, Theses, and Dissertations.
7th ed. by Kate Turabian. Chicago: University of Chicago Press, 2007.
(Carrier Library Ref LB2369 T8 2007)