In 2006, Mark Dever, J. Ligon Duncan, Al Mohler, and C.J. Mahaney held a conference - Together for the Gospel. Each of them is from a different denominational background, but all agree on the essentials of the gospel & leave the minor issue disagreements aside. They are all friends and decided that a conference highlighting the gospel. They also decided to invite a few of their "heroes" - John Piper, John MacArthur, and R.C. Sproul.
Preaching the Cross comprises the main sessions of that conference. Mark Dever introduces the volume - how the book (and conference) came about, how the four of them met, and their background, and a little about their heroes. Then the book has each of their addresses in that conference, re-written, or tailored for publishing.
Each gentleman talks about the Cross in preaching, but all from different angles - justification, the Old Testament, with humility, etc. The Cross is the central event in our faith and these men point to importance in proclaiming it regularly.
The chapter by C.J. Mahaney was terrific. He wrote about the two priorities of a pastor - watching you life and watching your doctrine. It is not enough to just watch one or another , they must be equally focused upon. He writes about the consequences of not following through and the fact that this balance is something that we do not ever have to stop watching. Another important point made about this was the fact that watching these two things cannot be done alone. We need accountability and models.
This is a great volume and one for the encouragement and challenge of every pastor. I also encourage you to visit the T4G blog and think about attending the 2008 conference.