If you plan to use any of the thousands of online resources, be aware that information quality is not always guaranteed on the Internet. Experts in a given field do not referee Web sites seemingly related to their area of interest. Publishers are not checking content for accuracy, citations, grammar, etc. Librarians are not reviewing online information for relevancy to the field. In fact, there is almost no way to determine whether online resources are authentic or someone's personal opinion.
Domain names ending with .edu are educational sites.
This does not mean that the school endorses them. The site might be a student or faculty homepage expressing opinions, no facts. Domain names ending in .gov are governmental sites and will contain factual information only. To check the validity of the site, you can spot check a few key facts and ask for the opinion of experts in the field.