Chis Brogan has an amazingly good post here, 100 Personal Branding Tactics Using Social Media. The thing is, it’s great advice for organizations, too.
Follow this guy. He’s really, really good, and knows his stuff on this social media business.
Subscribe to his RSS feed (notice how easy he makes it on his site).
Notice how he builds community (he has a signficant and ever-growing following) by adding value. He promotes himself (quite well), but he does so by continually providing advice you just can’t live without if you’re trying to learn about new media.