I've been fortunate enough to meet Jeff Widman, a solid believer with a tremendous amounts of gifts, skills, and abilities in relation to lean manufacturing and leveraging social media for all its worth.
From his insights I've been able to glean some key skills/tactics for using Facebook effectively for minsitry, specifically within Campus Crusade.
Here's a screencast I just did on how to use both Group Pages and Fan Pages effectively within your ministry. Hope it's encouraging.