Oh, and a word about age. While you may want to include your birthday on your Facebook profile, so people can message you on the big day, you should exclude the birth year, Dixson says. Your friends and family know how old you are, and there's no reason for your professional ones to know.

3. Posting content, links, and news

Thoughtful: Post content that highlights your personal interests and your professional areas of expertise. A marketing professional might post some interesting links for a relevant trade publication he or she wanted to share, for example. Posting personal picture slideshows is fine — again, within reason. You clearly want to avoid the aforementioned pitfalls of displaying shots of wild revelry. But for all the agony about what's acceptable and what's not, remember that offering contacts a decent glimpse into what makes you you can have business benefits. "It strengthens relationships," Dixson says. "It really helps establish connections. People like to do business with people they know."

Thoughtless: Spamming people is a big no-no, as it can irrevocably ruin your social capital. It's great to be so passionate about things in both your professional life and personal life that you feel compelled to share it with people who are important to you, but remember that people can only take so much time out of their day. Also, don't assume they care about every little thing in your personal life. People know you're proud of your kids, for example, and that speaks to your commitment as a parent. Yet you need to know when to draw the line somewhere in how much they want to hear.

Definitely keep your romantic break-ups and get-togethers in private forums, like e-mails, IMs and (who still uses it anymore?) the phone.

Oh, and this one should be self-explanatory: don't go flapping your gums about your company's affairs.

4. Talking to One vs. Many

Thoughtful: Posing a question to your entire network is OK, provided it's relevant to all of them, or at least won't be viewed as a nuisance. For instance, you might ask, "Getting a new phone. iPhone or BlackBerry?" Such a question will be relevant to a lot of folks who have gone through the same issue. The key is, if you're on the receiving end and want to weigh in on such an issue, be sure to respond to that person only — unless it's been made clear that he or she wants your comments public. This way, you avoid spamming people.