The Cross from a Distance, by Peter Bolt, was recommended to me as a commentary on the book of Mark.  Unlike scholarly commentaries, the book is not very technical.  Instead, it offers a fresh outline of this earliest Gospel as a series of events pointing to the Cross.  As such, it concerns itself with the structure of Mark as a whole and puts each pericope within the context of Jesus' atoning death.

The book is part of the New Studies In Biblical Theology series edited by D.A. Carson.  I would recommend The Cross from a Distance for small groups studying the book of Mark, as a companion text, to help facilitate group discussion.  Within a small group, it will offer value to the non-believer, new believer, and lay Christian, due to its logical, biblically grounded analytical approach.

For exegetes, the author's use and index of Biblical and non-Biblical ancient sources is helpful for in-depth exegetical studies. 

For those called to evangelism, the book offers a remarkably "uncluttered" presentation of the work of Jesus Christ which could help enable one's explanation of Him to unbelievers.