Disciple Making Movements (DMM) and Church Planting Movements (CPM & T4T) page of the wiki provides helps in growing disciples particularly in group contexts.
New Life in Christ > The New Life In Christ discipleship manuals were designed to help Christians grow. The lessons will help new believers take their first steps towards victory in their Christian life. The original volume was written in Spanish, and later translated into English, Russian, Ukrainian, Romanian, German, Tagalog, and several other languages. Recommended by Craig Nordgren.
Personal Disciplemaking: A Step-By-Step Guide for Leading a New Christian From New Birth to Maturity by Christopher Adsit. Recommended by Brett Hamilton. “He lays out a type of grid of discipleship through various phases of growth (baby, child, young adult, adult) with key spiritual disciplines (prayer, witnessing, word, family, etc). It is a helpful tool to be aware of needing to repeat certain foundational truths at various depths and not to dump the truck of theological truths too much or too fast on a young growing believer.”
Grounded in the Gospel: Building Believers the Old-Fashioned way by J. I. Packer and Gary A. Parrett about using catechesis as a form of disciple-making. See Gary Ridley's blog post reviewing this book.
Online course with our partners at WorldTeam called: Discipleship: Growing Mature Followers of Jesus with challenging content and stimulating discussion with other learners who see the critical role of discipleship in church planting among the unreached.