This document provides an introduction and overview of Twitter. It discusses common myths about Twitter, what Twitter is, and the benefits of using Twitter. It demonstrates how to set up a Twitter profile, follow others, retweet and reply to tweets. It also discusses using hashtags to find tweets on specific topics and how the "backchannel" on Twitter allows users to participate in live discussions of conferences and events they cannot attend in person. The document concludes with challenges for users to start engaging with Twitter through actions like participating in a tweet chat, following others, and tweeting about their work.