Succinct article from the New York Times today about marketing with Facebook,
Quick Tips:
Identify a short list of goals before you begin.
Show some personality in your page.
Don’t shill. Use your page to engage-and trust that sales will follow.
Use Facebook data to analyze your customer demographics.
via Small-Business Guide – Marketing Your Business With Facebook – NYTimes.com.
also of interest: Facebook Group vs Facebook Fan Page: What’s Better?