FOLLOW THE 5 W's
Who: Who wrote the pages and are they an expert? Is a biography of the author included? How can you find out more about the author?
What: What is the purpose of this site? What is the URL of the site and what might that tell you about its purpose? What aspects of the site make it difficult/easy to use? (For example: typos, easy navigation, nice layout, images, too much advertising, etc.)
Where: Where is this information coming from? Is there an "About Us" on the site to read about the publisher or who is responsible for the site?
When: When was the site last updated? Does the site even have a date? Does the currency of the information directly impact your subject?
Why: Why is this website useful for your research? Why should you use this information? Could you find the information through a better source?
Since anyone can put information on the web and it is not reviewed, always read the "About Us" section on the website to check for information about the author and the sponsor of the site.