Soma School (Audio and Notes) - a wealth of training resources for making disciples who make disciples

Gospel Centered Life (email Zac for a copy) - a wonderful 9-session study on how the gospel shapes every aspect of life 

Desiring God - The ministry of John Piper, holding a huge wealth of resources for growing in the faith

Grow - A FREE E-book on "reproducing through organic discipleship"

Fight Clubs: Gospel-Centered Discipleship (email Zac for a copy) - A great book on a great alternative to "accountability groups"