I am not going to put it unless FB gets tired and makes it essential for everyone.
Simple rules about privacy.
1. Don't put any material that you do not want to be disclosed online in the first place.
2. Use a separate browsers for FB and browsing other sites. FB also tracks you after you leave the site. Do not do any financial transactions in the same browser. Clear you cookies often.
3. Do not trust any of the companies be it FB, Google or anyone else.
4. Do not be fooled by the argument that it's a free service. Technically it is but not in the way you think.