There is a handy acronym for determining a source's credibility and it is called the CRAAP Test. Each one of these should be evaluated separately and each one has its own set of questions to consider for each source you maybe using.
The practice of resource evaluation involves a researcher taking an objective look at a potential source of information and making a reasoned and well-informed decision about its credibility and accuracy before determining whether or not it is an appropriate resource for a particular paper or project.
Researchers are likely to find multiple resources for nearly any topic, but not all resources will be equally suitable for use in an academic work. Resource evaluation is important because the quality of any subsequent work will often be dependent on the quality of the source materials used.
There are many factors you want to consider when evaluating a resource.
Ask yourself the following questions:
The list above is not meant to be exhaustive, and many resources will present other factors that will need to be considered.
Library staff can assist with the evaluation of a resource, but it is ultimately up to the researcher to decide what is/not an appropriate resource.