This document discusses using social media platforms like Twitter, Diigo, and LinkedIn for information gathering and professional networking. It provides background on each platform, describing Twitter as a microblogging service, Diigo as a social bookmarking and annotation tool, and LinkedIn as a professional networking site. It then gives basics on how each platform works and how to use features like tweets, bookmarks, tags, profiles, and recommendations. Finally, it discusses using the platforms together through browser plugins and mobile apps, and the importance of ongoing engagement and housekeeping for effective social networking.