How and what do I change in my privacy settings on Facebook?

[Terence]

Every Facebook user has the ability to customize his or her privacy settings. To edit the privacy settings for your own Facebook account, choose the "Privacy Settings" option from the Account drop-down menu available from the top right corner of every page.

Control who can see your information from the Basic Directory Information section.
Control who can see the content you share by selecting one of the four global privacy setting groupings (Public, Recommended, Friends of friends or Friends only) in the "Sharing on Facebook" section. If you'd like to further customize these settings, click the "Customize settings" link.
Control how your information is shared externally from the "Applications and Websites" section.
Block specific people or applications from interacting with you on Facebook from the "Block Lists" section.