If you are an author, published or not, there are two new Twitter hashtags that you'll likely want to follow: #waystoimpressbooksellers and #dearpublisher. The latter will probably be of passing interest to many book lovers as well, as will the often funny #bookstorebingo.
If you're not familiar with hashtags, or with Twitter, for that matter, the easiest way I know to cut through the incessent noise to find the good stuff (whatever your definition of that might be) is with TweetDeck, a free tool that you can download to your desktop. Once you download it, you simply login to Twitter via TweetDeck using your usual login and password. If you're already following people on Twitter these messages will automatically show up in one of the columns, while another will track retweets, direct messages and so forth.
That's a good start for managing your tweets, but where TweetDeck really comes into its own is when you start setting up specific searches for hashtags. Hashtags are simply words, or condensed phrases, with the hash symbol in front. Many Twitter users use these to help target their tweets to a particular audience, or to follow conversations on a particular topic. For example, if I set up a search for #books, everytime somebody posts a tweet that includes "#books" it will show up in one of my columns, irrespective of whether I already follow that person. In the same way, if I want to write a post about, say, libraries, I'll use the #libraries tag so that my message has the potential to be seen, not just by people following BookBrowse, but also by anyone who is following the #libraries thread.