The phrase "follower of Jesus" like the term "Christian" has become so generic that it means nearly anything and sometimes almost nothing. In Follow Me, the Lutheran New Testament scholar, Martin Franzmann, digs deeply into the Holy Scriptures to show what it means to be a follower of Jesus, written in an accessible style.
This isn't so much a study on the concept of discipleship in the gospel of Matthew so much as it is the author's running reflections on the text of the gospel. While discipleship is highlighted many times, the focus of the volume is Christ himself and what he does for us (i.e. the good news of the Gospel message). Personally, I think there should be a different title to the work but it is otherwise a good read for a reflection on Matthew or perhaps a lay study.
I like to go through a commentary on the gospel we will be spending most of the time with in the upcoming year. This is a wonderful commentary on Matthew, written in an elegant, poetic style. Different than other commentaries in that it gives an overview of the book rather than a strict verse by verse account. But it is very insightful. It is a print-on-demand book - go directly to Concordia Publishing House to order it rather than through Amazon. It will be worth it.