The Rough Guide to Social Media for Beginners is an excellent book for the newbie to social media. I found it very informative, and it contains a lot of step-by-step pointers with wonderful helpful pictures.
Facebook, Tumblr, Twitter, LinkedIn, and Google+ are all touched upon enough to give even the greenest computer wiz the confidence to start using them.
I highly recommend this book for youth, adults, and seniors that may want to start working in these social media realms. It may also be helpful for the intermediate user to hone their skills.
~ cross-posted on Goodreads