Below are some very good resources we would recommend for you. These guides will help you learn more about how to evaluate online content:
Evaluating Web Sites: Criteria and Tools
Evaluating Information Found on the Internet ( Johns Hopkins University )
Distinguishing Scholarly Journals from Other Periodicals ( Cornel University )
Critically Analyzing Information Sources ( Cornel University )
Evaluating Web Pages: Techniques to Apply & Questions to Ask ( University of California )
Five criteria for evaluating Web pages ( Cornel University Library )