Online Library of Social Media Background

If you're looking to learn more or solve some problems regarding social media, Shel Holtz has recently posted a great online resource list of social media information.
There are primers on social media and articles on blogs, podcasts, and social media demographics, as well as links to more than a dozen books that have already been written on the subject.

Here's that link again to Shel Holtz's social media resource list.