Advice for FaceBook newbie?

After years of adamantly refusing to join FB, I finally caved, but I want to make sure that I don’t spend a ton of time on the site and that I don’t get “addicted.” Also, I want to make sure that I don’t spend too much time comparing my life to other peoples’ profiles. (Yes, I know that a profile is not entirely representative of one’s life.) I am sure that a lot of this is just commonsense, but I would be interested to hear your input as to how you handle some of these issues. Thanks!