You can also order the Twitter Survival Guide there ($24.95). Such a book may seem unnecessary, but Twitter has become so big that you want to get it right whether you are a business owner or an individual.
Here is how they describe it:
"Whether you are building your personal or professional brand, looking for a way to occupy free time on your morning commute or staying abreast of breaking news, Twitter can be a powerful tool that leverages both online and offline communities with the unique format of microblogging. The Twitter Survival Guide will tell you about the proper etiquette that goes along with building your Twitter brand, and offers a wealth of hints, tips and tricks on how to use Twitter to achieve your goals."