I found a hilarious video entitled "How To Not Suck At Facebook" recently and made it the highlight of my most recent post at The Student Branding Blog. The advice is right on and consistent with what I always tell people about Facebook. In the video they say don't friend your boss, but my advice is behave on Facebook in a way that it won't matter who you friend, your boss or anyone else.
Never post anything, anytime, anywhere online that you would not be comfortable with anyone seeing. Any privacy you think you have online is truly virtual.
Watch the video, it is short and very funny.