The irony of it is that when I was in college, I didn't want to read. I was a typical athletic guy who was usually outdoors, and I preferred not to be indoors reading. When I arrived at seminary I had no choice. So I just began to read and, of course, it was all about what I wanted to know.
I really fell in love with reading theology. So now I read theology--books on doctrine--and commentaries. Every week of my life, I read all of the commentaries on any passage I am preaching, and then I just read theology. This comes in many volumes that deal with divine issues or divine themes, not just in theology textbooks, but also in books that deal with particular doctrines and doctrinal issues like the Holy Spirit, Christ, sin, or salvation.
For variation, I then sprinkle in biographies of spiritual men and occasionally a really "hot" book on important contemporary issues.
Click here to see some of the books that have most impacted John's life.