This document provides an overview of Twitter and microblogging. It defines microblogging as short, fast, easy blogging that can be done on mobile devices. Twitter is introduced as a microblogging platform where users answer the question "What are you doing now?" in 140 characters or less. The document outlines how to create an account, post tweets, follow other users, and use hashtags. It also discusses how Twitter can be accessed via the web, clients, email and SMS. Examples of how organizations, public figures, and individuals use Twitter are provided.