I recently attended a training session for small group ministry (they called it 'leadership' but wrong concept...its ministry: service).
The session touched on some biblical material...mainly about diligence in action, and it had a little of a Brookfieldian flavour, but was fairly mechanical, I thought.
In the time available it was possibly helpful for those who were new to small group ministry, but the big omission was the theological basis for meeting in small groups. There is one, and it is about the community together in mutual service; it is also about reading and talking together about the Word of God. None of this, or the theological outcomes were mentioned.
There was far more that could have been done from the perspective of using discussion as a means of teaching. Brookfield has some material on this (more articles here). The only problem is that lead by the Holy Spirit, discussion can go places that aren't lined up with where some remote author of study material thinks it should go...dangerous for authors who think they know where it should go!
In that connection, Jack Mezirow's Transformative Learning is worth some consideration.