Two link tips for some background reading, if you have a lot of time at hand:
If you’re in need of social media case studies, there is a really extensive meta list as compiled by Robin of the Interactive Insights Group. Meaning: it’s a list of links to sites with lists of casestudies. Nothing you can read in one go, but definitely something for your bookmarks.
Secondly, there is a gigantic list of the best internet marketing posts of 2009, as compiled by Tamar Weinberg. Again, bring some time along – or just bookmark it for future reference, as I did 🙂
(both found at steve rubels lates links.)