1. By default, your privacy settings are set to the slackest possible levels, so it’s up to you to adjust them. Many of Facebook’s privacy controls are opt-out, so you have to make a point of opting out or Facebook will share your information.

2. You can update your status, post pictures or videos to your profile, and do all kinds of other fun stuff from your cellphone using Facebook Mobile. (There’s even a special version just for iPhone users.)

3. You can tell Facebook what kinds of stories you like to see on your news feed. If you like a story, click the thumbs-up icon to see more of those kinds of stories in the future. If you don’t like a story, click the X to make it less prominent and see fewer of those kinds of stories.

4. Adding applications gives the applications’ creators access to all of your profile information. Keep in mind, too, that applications can potentially also contain viruses (dubbed social worms) that affect both you and your Facebook friends.

5. You can import an existing blog into Facebook’s Notes feature.

6. You can rearrange the sections of your profile (except the mini-feed, which you can’t move, but you can collapse.)

7. You can create multiple Friend Lists to organize your Facebook friends however you like: For example, all your work buddies, all your book club buddies, and so on.

8. You can see a list of when you met your Facebook friends in real life by viewing your social timeline.

9. You can add applications that let you create Facebook profiles for your pets: Catbook, Dogbook, Horsebook.

10. In certain circumstances, people you haven’t explicitly granted access to your profile (people who are neither your friends nor fellow network members) can see it: For example, hiring managers, Facebook application developers—and the police.

11. Facebook counts among its financial backers a venture capital company with ties to the U.S. Central Intelligence Agency.

By the author of Facebook: The Missing Manual, E.A. Vander Veer.