About a year ago, I interviewed my friend, Jonathan Dodson, about his book, Fight Clubs: Gospel-Centered Discipleship. Since then he's started a website with resources for you to learn more about how you can start gospel-centered accountability groups in your church. Recently, he spoke at Brent Thomas' church (another friend of mine) about this topic. He reminds us to 1) Know our Sin, 2) Fight our Sin and 3) Trust our Savior. I encourage you to listen.
Other resources you may be interested in:
Starting Fight Clubs: