The Supremacy Of God In Preaching – John Piper
Short, but impactful. I first read this book 5 years ago and have referred to it every time I prepare a sermon since then. Piper lays out in a way that only he can what preaching should be all about. He presents a way to preach all of the Bible to make much of the Cross to bring Glory to God. If you have any form of preaching ministry then you need to read this book.