Haven't had a chance to investigate this one Internet research tutorial closely but it looks promising...

Internet Detective, a free online tutorial designed to help students develop the critical thinking required for their Internet research, in the RDN Virtual Training Suite at: http://www.vts.intute.ac.uk/detective/
The tutorial offers practical advice on evaluating the quality of websites and highlights the need for care when selecting online information sources to inform university or college work.

Have a look!