Read a sample chapter from the Twitter book (also available as PDF).
Tim O’Reilly, the founder of O’Reilly Media, has written an illustrated guide on Twitter – The Twitter Book – that promises to teach you everything you need to know to quickly become a Twitter power user.
Unlike the other O’Reilly titles, The Twitter Book is presented in a colored format with practical examples (using screenshots of real tweets), links to interesting mashups, best practices and essential Twitter manners.
Here’s another interesting excerpt from the Twitter book:
When via is better than RT
Write a note that tells the world what this link means to you. Then use via to tell the world who showed you the link in the first place. (Via is also great for giving credit when you got a link from a source who isn’t on Twitter.)
In an ideal world, use literal retweets only when the original phrasing is unique and a key part of what you want to pass on. A straight retweet should show the character of the person making the original posting, not just a link. Unless, of course, it’s news that’s just so hot that you have to pass it on before it burns your keyboard.
Also see: Twitter Guide from Digital Inspiration