Start here and read: http://en.wikipedia.org/wiki/Twitter
Ask yourself why would you do this? – I started using Twitter primarily to expand my media reach and relationships with reporters and editors on behalf of my clients and my own professional development. It has since become a powerful business and social networking platform that I use actively. The beauty of Twitter is its ultimate level of customization. Many younger users Twitter just to keep up with their friends in a broader way than text messaging would allow. NOTE – it is important to be patient and persistent in building your network of followers in order to use this tool effectively.
Log on to http://twitter.com
Pick a user name and password. Picking a user name is VERY important and varies based on your purpose for that user.
Some users use either their real names or something very close to it – as I do, @pdsnyder. These users are prepared for EVERYONE to know what they’re saying because Twitter is part of the viral, social media beast from which we benefit, but can also get VERY quickly burned. For business users, this requires a high level of caution in what/how you Tweet.
Some users pick fictional names or nicknames as their "handles" to remain relatively anonymous (except to their close friends). This gives them a freedom of expression that identifying their real names would eliminate.
Go find some friends that have Twitter feeds and see who they’re following. You can search Twitter by last name or user name. Since many last names are common, you will often have to sift through many users before you find your friend. www.search.twitter.com is also effective for finding friends and other users that share your areas of interest and expertise.
Review a few user feeds and start following some people.
Tweeting consists of answering the question, "What’s happening?" in 140 characters (characters, not words) or less. Any links count too, which is why websites that compress like http://bit.ly are popular.
Four habits of effective Tweeps (people who use Twitter, particularly those people that follow you, or that you follow)
They provide news and data on their area of expertise
They re-tweet (RT) news and data from other Tweeps that they believe is valuable
They keep their posts to Twitter to 120 characters or less to encourage re-tweets
They tend not to suffer from Twitterhea (Tweeting too often or irrelevantly)
They give a sprinkling of Tweets about their personal lives (I do this about sports, playing poker, and travelling)
Effective Tweeps enjoy larger numbers (and higher quality) of followers
How to increase your following
Re-tweet other Tweeps’ tweets
Engage directly with your followers via “@” replies or direct messages
Request re-tweets on news that you believe is very important or relevant
Refrain from Twitterhea
Respond or reply to requests for information to Tweeps you’re following (there is a reply function at the end of each tweet that comes into your feed)
Ask friends or colleagues in other correspondence if they tweet, and if so, what their Twitter handle is
Include your Twitter "handle" in e-mail signatures if you use it for business purposes