One of the biggest problems students have with using websites in their academic work is the accuracy of the content. Here are some basic ways to evaluate a website.
What does the domain name tell you?
Who wrote the page? Is there a page author listed? If there is no author, is there a company name? Is there contact information listed? If there is no one listed that takes responsibility for the page you should take that into consideration.
Here is a link to a reliable site that will help you with your evaluation:
UC Berkeley Web Evaluation Tips