If you use a web page as evidence in a paper or presentation, you have to be prepared to show that you've considered the following issues, some of which should look familiar to you.
Authority: Who wrote this information? Why should I believe what they say?
Accuracy: Is this information correct?
Objectivity: Is this information objective, or is it biased in some way?
Currency: How current is this information?
Coverage: What topics are included, and to what depth are they explored?