Webware published a very good introduction to Facebook: Newbie’s guide to Facebook. This introduction gives you:

• A definition of what is FB
• The way to setup an account/Profile
• Advices on security/Privacy settings
• A definition of Poking and how to use it
• Advices on the way to share information with friends
• A short description of the FB platform
• A list of addons to enhance the FB experience

I would have loved to find this introduction on FB earlier when I was a newbie to FB.