Keller outlines his approach to handling scripture which is Christological, and takes us through the engaging the heart with that. Clowney contributes from a lifetime of experience in showing way scripture is about Jesus - from which we could all learn massively.. Keller shows how he prepares to preach and the way that he's learned from people like Dick Lucas. You can see why people are raving about Keller.
Listening to this series of lectures could be the best use of 18 hours of your time.
And also adding these to my iPod Together for Adoption mp3s by John Piper, Justin Taylor etc.