Ask these questions to get a sense for whether your source is reliable:
Ask who is responsible for the information.
Are they qualified to teach you? What are their qualifications? Do they have a name, and can you contact them? Why are they providing this information?
Ask whether the information can be verified.
Do other sources agree? Are they providing citations so you can follow their research?
Ask how current the information is.
Has the field of research changed significantly since the information was published? Does the research deal with all relevant discoveries or information? If the information is several years old, what holes might exist in the research? Can you fill these holes with other sources?
Ask whether the information is objective.
Does it present both sides of an issue? Is it designed to persuade you? Does anything about the information seem fishy?