Critically reading the web means validating web based information much like one would determine the validity of information obtained from print, television or any other medium.  I believe it is important to assume the information received from an online source is invalid, biased or otherwise skewed until the reader determines the source, purpose and the writer's/publisher's intended audience.

In the classroom, one could demonstrate the process of critical reading and validation by comparing stories and information obtained from several print sources with varying degrees of credibility, such as The National Inquirer, Time, People Magazine, Local Newspapers, National Newspapers and School Newspapers, Encylopedias just to name a few.  The students could discuss credibility issues.  The next step would be to look at the web.  The students could compare information on known topics from several websites  as they did the print sources.  Finally, students could practice rating web sites containing information that they are unfamiliar with.