This is a website where you can share book recommendations, keep track of the books you are reading, want to read, and have read, and write reviews of books.

Another social media site, where you can catalog and keep your book collection organized.

A website similar to LibraryThing and Goodreads, on which you can organize your books on virtual bookshelves.

This article provided by YALSA gives some great suggestions on how to use social media to teach young adults in either schools or libraries.