The Internet is a vast source of information, but not all websites can be trusted and all should be evaluated before using for your research. The CRAAP Test (from CSU Chico) is a good tool to evaluate the Currency, Relevance, Authority, Accuracy, and Purpose of all of your sources. Use the CRAAP Worksheet to evaluate all the websites for your research.
This short video from Portland State University shows how to use the CRAAP test to evaluate websites.