Here’s a decent article from Microsoft on Social Network Safety. It covers things like being aware of how what you post could be used against you, not letting apps access your address book, using social networks at work, and talking to your kids about protecting themselves. For experienced techies it’s worth a quick read to refresh your memory, for everyone else it’s a good article you might want to forward to your friends and family.
http://www.microsoft.com/security/online-privacy/social-networking.aspx?sf4883013=1