When evaluating a web site, check these basic points:
Author – if you cannot determine who is responsible for the content of a website (either an individual or organization), you won't be able to gauge their expertise or relationship to the subject.
Domain – the last segment of the "root" of the URL (for example, hnu.edu) will tell you if the source of information is educational (.edu), governmental (.gov), or commercial (.com).
Date of creation or revision – it is important to establish that any content containing data, facts or statistics is up-to-date and still relevant.
Intended audience – if the content is intended for an academic audience, the website should provide information that can be verified using citations or external links.
Purpose of the information – the ratio of content to advertisement will tell you whether the site is being used to inform readers, or to make money.
Science.gov searches over 60 databases and over 2,200 scientific websites to provide users with access to more than 200 million pages of authoritative federal science information including research and development results.