According to Wikipedia, citations for World Wide Web pages typically include the following list below. *Caveat:* you may not be able to determine all of the information below, but if you are fairly certain you're using a reputable source, include as much of the information below as you can:
Primary sources include the following:
Most often, primary sources used in Wikipedia are a form of illustration. They illustrate what reliable secondary and tertiary sources learn about the discussed topic. Illustrations are a valid part of any encyclopedia, but should not outdo the content based on secondary or tertiary sources.
[Text adapted from Wikipedia's Use of primary sources in Wikipedia.]
Forthcoming!