Step 1: Got to Twitter.com and sign up for an account. If you’re not following at least 25 people the experience is kind of lost (some reco’s below). If you tried it before and didn't follow 25 people it doesn't count. Try it again.
Step 2: Download and Install Twhirl
Step 3: Using Twhirl search for people that talk about what you’re interested in, follow the ones with interesting things to say. If you like cooking, search the word "cooking"
Step 4: Once you observe Twitter users you think are providing you value, and you want to get in the coversation, base your post frequency, style, and topics on them.
Here are some people worth following if your a marketer, you can quickly add them by clicking on the Following link from my Twitter page
JasonCalacanis / Jason Calacanis - Cocky, opiniated entrepreneur. Owns Mahalo.com
Scobleizer / Robert Scoble - Classic Geek, Loves Technology and Business
jowyang / Jeremiah - Social Media Expert from Forrester
loiclemeur / Loic Le Meur - Owns Seismic, great video's
Armano / David Armano - Designer
darrylohrt / darryl ohrt - Planner
bmorrissey / Brian Morrissey - Ad Age Writer
skydiver / Peter Shankman - Social Media/ PR guy/ high energy creative plane jumping nut
guykawasaki / Guy Kawasaki - Old School Apple Marketer gone VC
THespos1 - Tom Hespos - Agency Owner
mediadarwin - Jim Meskauskas - Gifted Media Expert, Dayjobbing as a Pirate
chucknorris_ - Chuck Norris - Beat a brick wall in a game of tennis
rgleeson / renny - World Wide Digitist
TechCrunch / Michael Arrington - Will tell you who's getting money, who's great, who sucks
ischafer / Ian Schafer - Digital Agency Owner, Creative, Daring, Interesting
sarahcuda / Sarah Lacy - Much harrassed but bright business writer
jasonclement - Search guru
daveknox - P&G brand manager
adrants / Adrants - They know when you are lame