Websites vary immensely in quality from very reputable to down right fraudulent.  There are many ways to try to decipher the good from the bad; however, always use judgement.  Look for several indicators to establish quality:

• What is the URL? [Uniform Resource Locator] Is it www.ibm.com or www.joeinthebasement.com?
• Remember that anyone can purchase web space as a .com.  This is not to say that all .com sites are suspect but an .edu [education] .gov [government] .net [network provider] .mil [military]  .ac [education in Britain] .org [organization] are much more reliable.
• Try to get to the root of the initial part of the URL.  That is, is the information from www.honda.com or from www.joespage.com/interests/honda/index.htm? Chances are the information about the main honda site is much more reliable
• Even at reliable sites such as the Greenpeace home page, remember that some organizations have a particular view point
• Is there bias? Are all view points fairly represented?
• What is the year of the website? Is it up to date? Look for a copyright date.
• Who endorses the page?  Who advertises on the page?  Are they reputable?
• Do the links at the site point to reputable sites.  Reputable sites tend to recommend other reputable sites
• Who wrote the article?  Not many web articles are signed, but if the article is signed, who is the author? Does he/she has any qualifications? MD? P.Eng.?