•Private matters. Facebook has been described as a party where you need to assume the entire room can hear you. Learn the terminology. Wall-to-wall posts can be seen by others. Send a private message if you want to keep an exchange under wraps.
Familiarize yourself with the privacy options, found under "Settings." You can determine who among your network (friends only, friends of friends, etc.) can view your user profile, personal info, status updates, photos and videos tagged of you, friends lists, wall posts, and education and work information.
It's also a good idea to group friends into customized Friend Lists, perhaps one for professional contacts and another for school chums. You can apply different privacy settings to those lists. Your bosses need not relive your college exploits.
Generally think long and hard about the information you reveal in your profile, from the year you were born to political or religious beliefs. But you're likely to get as much out of Facebook as you put in, so withholding too many details may be counterproductive.
One of my Facebook friends, Roger Matus, CEO of e-mail archiving company InBoxer, recommends three tests before posting: Would you be upset if your mother saw it? Would you be upset if the most nefarious person you ever heard about saw it? Would you be upset if it was on the front page of USA TODAY?
It's all a balancing act of sorts. What good is a social network if you're too timid to be social?