In week 7 there is the seminar discussing an article on Wikipedia. Before that there is a session on Web 2.0 and social media more generally. As a starting point, there are some links etc. to explore on this page: http://www.netvibes.com/sheilawebber#Web_2.0_in_general
I haven't finished updating these pages - I should have done before the session on Tuesday! However, the links on this page do all work (at least when I tested them just now) and the material there is still useful.
Also, here is a useful powerpoint from Karen Blakeman