Also available as an ebook:
List as much of the following information as possible (you sometimes have to hunt around to find the information; don't be lazy. If there is a page like http://www.somesite.com/somepage.htm, and somepage.htm doesn't have the information you're looking for, move up the URL to http://www.somesite.com/):
Author, A. A., & Author, B. B. (Date of publication). Title of document. Retrieved month day, year (only if the text may potentially change over time), from http://Web address
NOTE: When an Internet document is more than one Web page, provide a URL that links to the home page or entry page for the document. Also, if there isn't a date available for the document use (n.d.) for no date.