“Sure, you use the Internet all the time, but you need to wise up to the web when you use it for your university or college work.”
Visit the Internet Detective to learn about doing research on the web.
Sometimes Wikipedia articles will link to reliable sources in the "References" section, but you still need to be careful.
Check the url of the website you're looking at:
For more ideas about how to evaluate websites, visit the Internet Detective or ask a librarian.