Evaluating Websites
It is especially important to critically evaluate any websites you reference because information found on the Internet is not regulated in the way that information in databases and in scholarly journals is regulated. You are more likely to run into information that is inaccurate, outdated, and/or biased. You may also have a harder time determining the origin of the information (author, publisher, whether the content is original).
Website URLs
The old standby that .com URLs are bad, whereas .edu, .org, and .gov are fine is overly simplified.
In health care, dates are very important when analyzing information, so if you find information from a .gov site that hasn't been updated since 1998, it is probably information you might want to scrutinize. In addition, trade publications often have .com domains, but contain valuable quality information. A lot more goes into analyzing results than just the domain.