We found this helpful list of things NOT to share online at news.trendmicro.com:

• Confidential information about your identity –  This includes your address, phone number, social security number, and birth date. Don’t share this information about other family members either.  This is the information that identity thieves seek. Don’t make it easy for them by posting it for the world to see.
• Financial information – Keep bank account numbers, loans and credit card information close to the chest.  It’s generally safe to use online banking and make purchases with credit cards on reputable sites, but make sure the web address is “https,” which means that there is extra security.
• Your schedule –  Don’t advertise that your house will be empty for a week while you are at Disney World with your family.  You may also want to be careful about posting where you’re going during the course of your day.
• Work information –  Be cautious about posting information about events at work. You don’t want to reveal confidential information about your company or clients.  Also, you should refrain from posting comments about your boss or co-workers.
• Passwords or information that could be clues to your password – While it may be obvious that you shouldn’t post passwords online, you should also make sure you don’t post information that could allow a scammer to figure out your password. Think about the security questions you are asked and make sure that information stays private. Common security questions include: The name of your street where you grew up, your mother’s maiden name, your elementary school, your first pet, your maid of honor or best man and your favorite movie, color or food. If you feel that any of your passwords may be at risk, change them and pick new security questions as well.

Always assume that anything you share online can and will be shared, and not always in a manner that you would like.  Go for an air of mystery and keep this information private!