Before using any information source in your paper, whether it is a book, article, or something from a webpage, you need to carefully evaluate the information to make sure it is both reliable and appropriate. Use this list of questions to help you evaluate information. Depending on your information need, different criteria will be more or less important.
Additional information at - Evaluating Web Pages: Techniques to Apply & Questions to Ask Steps and Guidelines for effectively evaluating websites. (UC-Berkeley).
It is not always easy to figure out if online sources are credible. Below are four short videos showing some tools you could use to help you determine if a source is credible.