I just came across a new book called how Wikipedia works. It is available via Amazon but also free on http://www.howwikipediaworks.com/.

It describes the editorial process of Wikipedia and gives many useful tips to its users.

Here's one of the tips: On each Wikipedia page, about half way down the left-hand column, there is a Cite This Page link (in the toolbox section) that provides not only a permanent link to that particular version of the page and also offers citations preformated in a variety of citation formats. Here's the link to the page on Education:

http://en.wikipedia.org/w/index.php?title=Special:Cite&page=Education&id=246060397