First, gather the necessary information. 
Here's what you'll need:

• name of web page creator (if given)

• title of web site

• date of last update (if given)

• name of any organization associated with web site (if given)

• date you looked at the web site

• the web site's URL (network address)

All web sites are different, and many won't list the name of the creator or date of last update.  (Not a good sign!)  However, if you still want to use the web page, simply skip the missing information in your bibliography citation.