I'm more of a Twitter person, myself. Because I think of Facebook as the place for meeting people you used to know; Twitter for meeting those you want to know now.
But in my role as social media evangelist, I talk to plenty of FB newbies. Over 45 million signed up for Facebook in January alone. Where teenagers now make up no more than 12% of the population. In fact, the fastest growing FB demographic is women over 55. Which may be why this dandy Etiquette Guide is styled to look like a 1950s-era instructional film. (Props to YourTango.)