Between Weas and Rudel, I seem to always find myself in 3rd place. One day my friend, one day...

Careful with sharing still - basically only share information that you wouldn't object to virtually anyone knowing... while you may only share with one person... that person may have their wall publicly viewable, they may 'share' or repost "funny stuff" in a way you wouldn't expect... and their friend, or friend of friend may do the same...

Basically brains can become disengaged once logged into FB/Twitter etc.

While aimed at children, the HH websafe filmettes are quite valid for all:

Just go through all of the privacy settings after you sign up and basically be sure that everything is limited so only your friends can see it. Or restrict further if desired. You can add multiple emails to your profile so I think it's trivial to change which is primary.

Use a email address for FB that is not important since they will sell anything about you for money.

After you're up and running with Facebook, you can block all of the stupid game request that people send out. Also if it seems to good to be true don't click on it, I personally won't click on a link unless I hover the mouse over it. If the url in the footer doesn't match what is seen on the screen I'm not clicking.

Privacy settings:
Set all to friends only, or only me. Address and phone number should be only me, everything else you can be safe with friends only. I personally set my friend invites to "friends of friends", so I don't get spammed with the bots.

Turn off email notifications for everything, otherwise your email box will get spammed.

GREAT POINT!

I have mine set to an email address I rarely use or check. Last time I opened it I had a few hundred emails..."so and so liked your picture", etc. Now (a few months ago) I have all notifications turned off because I didn't know about that before.