If you want to learn more about missional communities, I would suggest the Verge Network or 3dm. Both offer plenty of insight and practical direction. I’d say that 3dm is the better route to take if you are thinking of developing missional communities in an existing church. The legacy of 3DM comes out of a traditional church – St. Thomas Anglican Church in Sheffield. As a pastor of traditional churches, I have found their perspective fits well with my experiences. In addition, they brought what they learned in England to the US about ten years ago. And their model for missional communities is tested and proven and they have resources and excellent training available.
In my case, I started developing an interest in launching missional communities when I concluded, as a pastor, that my churches and pretty much every other church I’ve been around have not been very effective at making disciples. What I’ve learned and now experienced has convinced me that missional communities offer one of the best pathways to renew my city, revive churches, and develop disciples of Jesus Christ who are equipped and motivated to make more.