What would be some of the basic areas you would cover in training lay preachers who have had no theological training whatsoever?
In training lay preachers I would focus on making sure they have a solid grounding in systematic theology that is based in Scripture and proven by the church over the centuries. This will help keep them on an even keel when winds of doctrine, promising “new” insights, blow across the church. Then I would focus on a basic hermeneutic or method of interpreting Scripture, in light of the way language works, and in light of the context of the Bible in the history of redemption. Finally, I would emphasize, for any and all leaders (whether those who can attend seminary or those who cannot), the importance of godly character as Paul places that “center stage” in his lists of qualifications of elders in 1 Tim 3 and Titus 1. These attributes of humility, holiness, integrity, etc., must be grounded in a firm grasp of the gospel of God’s grace, given in Christ and received by faith alone.
Find here the whole interview with Dennis E Johnson over at Expositionalistix. Personally, I would highly recommed Johnson’s book “Him We Proclaim” (reviewed here).