When you find information on the web, you have to be especially careful about evaluating it--checking to see if it's reliable and usable for your school work.
Here's a quick tip guide for evaluating any information resource, especially web resources.
When was this site last updated? Look at a few documents on the page—can you tell when they were written?
How important is this to you and/or your topic?
What is this site about? Is it easy to tell? What is the scope of coverage (broad, narrow, etc.)
Who do you think is the audience for this info?
What person or organization is responsible for this content? What are his/hers/their credentials?
What makes the author(s) an authority on this subject?
Is the information on the page supported by evidence of some kind? Does it include references to sources?
Are there spelling, typographical, or grammatical errors?
Who is the intended audience for this information? Is the site selling something, like a product or an idea?
Look for the About page of the site or a mission statement to help evaluate its purpose.
Ways to limit searches:
site:edu ==> educational institutions
site:org ==> nonprofit organizations (e.g., museums, historical societies, PBS sites)
site:gov ==> government sites (e.g., National Archives, Library of Congress, museums)