Evaluating sources is a key component of the research process. When evaluating there are a few thoughts to keep in mind so that you're making sure you're getting quality sources that support the topic you've chosen.
Use the CRAAP test to evaluate the information you find. Ask yourself the following questions about the resources you find:
Currency – Is it timely or up-to-date?
Relevance – Useful for your purposes?
Authority – Who wrote it? What is the source?
Accuracy – Are there references to back it up?
Purpose – Why was it written? Is there a bias?
