Students often ask, "How do I know it's a good source of information?" Start by asking yourself, "Who? What? Where? Why? and When?" Who wrote it? is s/he credentialed and qualified to to write on the topic? What is the point of this article? To inform, persuade, sell, scare? etc. More ways to evaluating information are below.
When you encounter any kind of source, consider:
Authority
Purpose
Publication & format
Relevance
Date of Publication
Documentation
Content courtesy of UC Berkeley Library