There are a few ways to use twitter:
Twitter whoring: follow EVERYONE and follow anyone in the security space. @Mubix does this and it’s worked well for him and me. If you chose to do this setup a separate twitter account for what I call “luminaries”, these are people who you don’t want to get cought in the shuffle of everyone else on your follow list tweets'. Then get a client like seesmic desktop and add both accounts. Yes I know some twitter clients support grouping but with a large following list twitter will not pull all of your follows when making groups, this is annoying. This has something to do with the API I think.
Selective Twittering: follow only people that you are interested in, or who post things you care about. This would be a kind of “luminaries” only account, you can also use a different account for twitter whoring in conjunction.
Promotional Twittering: Similar to twitter whoring but with a larger concentration of following security companies, magazines, etc. In this situation you will want to friend them, their sales peeps, editors, etc. Get friendly and get them to retweet your posts.
To get started, check out my “luminaries” account @securityaegis
People I’m following there are good ones to start with. That account includes Backtrack developers, popular pentesters, security icons, SANS instructors, famous exploit writers, security podcast hosts, con leaders, (e)hackers, and more.
If you have twit knowledge to add, post here. I’m always looking for more people or more efficient ways of doing things =)