Evaluating the quality and the usefulness of what you find is an important step in the research process, but it is one that is often overlooked. Consider the following reasons for evaluating information: anyone can post anything on a web page, information can come from a variety of sources, only some information sources are reviewed before publication, scholarly/peer reviewed articles are often required by your professors, and not all information is scholarly.
Using reliable and credible sources will help you avoid information overload and get better results.