There are several items on Wikipedia which I must highlight : Andreas Brockhaus and Martha Groom (University of Washington Bothell) gave a presentation at an EDUCAUSE Conference last year "Using Wikipedia to reenvision the term paper" Find out how students became more motivated through publishing their term papers on Wikipedia and learnt to deal with issues of voice, knowledge, and community.
Tara Brabazon (University of Brighton) wrote a critical piece in the Times Higher, 20/3/08 "Where fans put Franz before the Archduke". She lampoons the objectivity of Wikipedia by comparing lengths of articles on topics like Franz Ferdinand (the group) versus the Archduke who caused the Great War! A point well made but there's more to Wikipdia than this. She made similar points at the LILAC Conference, but when questioned is well aware of the possibilities of using Wikipedia in a positive way to teach students about how "information" is created.
Wikipedia : the missing manual, by John Broughton was referred to in Lauren's Library blog recently, and she relates some very telling points about how it shows Wikipedia could be used in an Information Literacy class.
There are some "guidance" pages on School and University projects on Wikipedia itself which may prove interesting.
Finally, if you want some basic sources for reliable online information you might try When Wikipedia Won't Cut It: 25 Online Sources for Reliable, Researched Facts, some standard alternatives.