Paul the Apostle: Missionary, Martyr, Theologian by Robert E. Picirilli is a critical examination of the life and ministry of Paul the Apostle. This is meant to be a middle of the road book, such as a college textbook. Paul the Apostle isn't for the casual reader, nor is it an in depth look at all the minutiae others critically examine.
This is a great resource for pastors and students of theology. It is kind of a slog to read straight through, but since that isn't its intended purpose, that isn't a huge problem. The writing is accessible and the structure is very easy to follow. Whether one wants more information about a particular letter, missionary journey, or time in Paul's life, it is easy to find what one needs. There is also plenty of other resources listed if one does want to take a closer examination of a particular aspect of Paul's life.