Summary of Five Criteria for Evaluating Web Sites
Accuracy. If your page lists the author and institution that published the page and provides a way of contacting him/her, and . . . Authority. If your page lists the author credentials and its domain is preferred (edu., gov., org. or .net) and . . . Objectivity. If your page provides accurate information with limited advertising and it is objective in presenting the information, and . . . Currency. If your page is current and updated regularly (as stated on the page) and the links (if any) are also up-to-date, and . . . Coverage. If you can view the information properly--not limited to fees, browser technology, or software requirement, then . . . You may have a higher quality Web page that could be of value to your research!
Quoted from an article in CR&L News July/August 1998, p. 523

Summary of Six Criteria for Evaluating Web Sites
Quality, depth and usefulness of content clear statement of the content, including any intended biases provides appropriate links to other Web sites attention to detail; absence of grammatical errors, absence of spelling errors, and so on Uniqueness of content - - Currency of content uniqueness of the resource as a whole; creativity links are kept up-to-date update frequency is appropriate for the subject matter Authority of producer authority and legality clearly stated if not easily recognizable, an explanation of the history and purpose of the organization Ease of Use - - Customer Service user-friendly design; easy navigation good search engine attractive; graphic design leaves good impression easy output (downloading or printing) contacts are responsive; e-mail addresses readily available Efficiency [note: efficiency is affected by a user's method of Internet access] graphics load quickly or are not so intensive as to seriously degrade access any required plug-ins are available for easy download realiable, speedy server Appropriate use of the Web as a medium components are well integrated (audio, video, text, and so on) useful information is still available, even if the user does not have all the plug-ins and media components effective use of JavaScript and other technologies
Based on the article Best Free Reference Web Sites, Seventh Annual List which appeared in Reference & User Services Quarterly, Vol. 45, #1, Fall 2005, p. 39

Sites with longer more elaborate evaluation criteria

All of the following websites are kept current, are updated frequently, and are authored by professional librarians or university faculty members

• Evaluating Sources: Internet Sources Purdue
• Evaluating Sources : Basic Criteria  an excellent basic list of questions to be used in evaluating resources. See also Distinguishing Scholarly Journals from other Periodicals on the same site
• Evaluating Web Content  SUNY Albany University Library
• Evaluating Web Pages: Techniques to Apply and Questions to Ask UC-Berkeley Libraries
• The Good, The Bad, and the Ugly, or Why It's a Good Idea to Evaluate Web Sources  New Mexico State University Library
• World-Wide Web Virtual Library: Evaluating Information Sources  One of the WWWVL's many well-maintained sites. This particular site is updated frequently.
• Virtual Salt: Evaluating Internet Research Sources  a retired University professor offers some interesting insights on web site evaluation; archived 2007

Additional Sources of Interest

• Research 101  Research 101 is an interactive tutorial about conducting research, developing research questions, and understanding how information is produced and distributed.
• The Virtual Chase: Teaching Legal Professionals How to do Research: Evaluating the Quality of Information on the Internet
• Publishers Wanted, No Experience Necessary: Information Quality on the Web  This article is archived and it may take a moment to load. It is a column written in 1997 by Genie Tyburski, a legal librarian. The content continues to be very relevant.
• Intentionally Misleading Web Sites an article in from techLearning an online resource for K-12 teachers.