Links to basic Twitter symbols and etiquette, as well as which hashtags are commonly used by writers and our ilk.
How To Twitter: Tips for Newbies, from Molly Greene
Twitter Hashtags for Authors & Book Marketing Pros – from publishing.about.com. A great list.
Twitter hashtags for Writers, Authors, and Self-Publishers, from Self-Publishing Resources
100 Twitter Hashtags Every Writer Should Know, from Aerogramme’s Writers Studio
A Whole Bunch of Oddly Specialized Writing Hashtags – do people really use all these?
40 Hashtags for Authors – from Training Authors. How many can I memorize?