In reading Patrick O’Keefe’s Managing Online Forums, the most significant lesson seems to be that starting an online community is a significant endeavour (there’s a long chapter on “Banning Users and Dealing with Chaos”). Another significant lesson seems to lie in the fact that the “Making Money” chapter is very short. If neither of these lessons are a deterrent, the book is a good survey of important considerations when creating a community, and has a few insights into the area of motivating users to contribute (“user promotion,” “member of the month,” “awards programs”). Like many real-life constructed communities, in my experience, online communities can start with a fury of activity and attention, and then slowly dwindle, and usually the path of least effort is going where your users already gather (Facebook, Linkedin, etc). But if you have the resolve to create your own, this book is a good reference.