This document discusses best practices and challenges for libraries using social networking. It begins by defining social networking and explaining why libraries should engage with patrons through these platforms. Popular social media sites like Facebook, YouTube and Twitter are described. The document then outlines how libraries can use social networking for goals like building community, promoting services and gathering feedback. Challenges of social networking for libraries are also presented. The bulk of the document provides best practices for libraries in using specific social media platforms effectively and developing strategies, policies and metrics for assessing their social media efforts.