It's important to be careful when using online resources. Many websites are biased or even present false information. Consider the criteria below when looking at a website.
Author: Is the author named, or are they anonymous?
Date: Is the article or website current and up to date? Is there a date on it at all?
Authority: Does the website tell you where it is getting its information from? How do you know it is factual?
Bias: Is the website's goal to inform or to persuade?
.com = commercial (ultimately trying to sell something)
.org = nonprofit (may want you to believe what they believe or donate to their cause)
.gov = government (usually reliable, but keep politics in mind)
.edu = school (usually reliable)
.net = misc. (this could be anything -- watch out!)