UPDATE: Since writing this, Mashable published the Twitter Guide Book: how to, tips and instructions. A must read for anyone trying to wrap their head around Twitter.
Need some help using Twitter? Check my top five tools and resources.
1. What is Twitter? – video from Common Craft
3. Twitter for business – should your company Twitter?
4. Twitter Tips – from ProBlogger Darren Rowse
5. Twitter resources – more excellent links to Twitter books, tools and resources
Webdesigner Depot has also written a guide to Twitter.
Tripwire Magazine has a 130+ Twitter toolbox which lists lots of useful Twitter tools all in one place. Another recommended read.
Read and ye shall be enlightened about how Twitter can be part of your marketing toolkit.