If I could only give you one book to take into ministry it would be Robertson McQuilkin's The Five Smooth Stones: Essential Principles for a Biblical Ministry.
Click on the title and go to my website www.royking.org . From there you can order the book and also download free exercises to help you integrate it into the choices you face in ministry.
In recent weeks in my coaching and consulting I have encountered the following from different leaders (and part of my counsel involved reading certain chapters in this book)
1. I need help in getting our missions program from random projects and trips to intentional strategic focus.
2. I have people choosing lifestyles very contrary to the word of God and yet twisting truth to try and say it is God's will
3. I do not know how to get people motivated for witness and church planting to reach people with the Gospel. How do I get people's hearts to break with what is on God's heart.
4. I cannot believe the messes people can be lost in. I want to connect them to biblical counseling resources to help them but how do I determine if a counselor is sound and safe?