1. It has a respected publisher.
Who manages the site? Knowing the owner/publisher of the site will give you further insight on the credibility of information published there. A good site will make ownership and authorship clear. Clicking 'About Us' is a good place to start.
The web address itself can provide information about the sponsor.
2. Information on the site is current and up-to-date.
The site should be updated frequently and reflect the most current information. Look for the copyright date (usually at the very bottom of the page) and/or a clearly posted latest revision date. Check links within the site, as broken links may indicate an out-of-date site.
3. The site's content is non-biased.
Information should be presented in a clear, factual manner. It should be non-biased and capable of being verified from a primary information source, such as scientific studies, peer-reviewed professional literature, links to other web pages, or other neutral references. Be skeptical of websites that contain endorsements/advertisements, or that seem to 'push' certain products.