The Flow of the Psalms, Discovering Their Structure and Theology by O. Palmer Robertson and published by Presbyterian and Reformed.
This book is a study of the Psalms as an overarching redemptive-historical progression rather than a random collection of unrelated poems.
For centuries the book of Psalms has been read as a random collection of individual poems with no discernible pattern of intentional arrangement. Augustine referred to the organization of the psalms as a "mighty mystery." Recent Old Testament studies insist that each psalm is not to be interpreted in view of its position in the overall book or by the psalms that border it. Yet O. Palmer Robertson shows that there is a clear redemptive-historical progression that develops throughout the five books of the psalms.
In addition, structural elements such as the placement of acrostic psalms, strategic couplings of a Messianic psalm with a Torah psalm, and the grouping of psalms by topics indicate an intentional structuring. The uncovering of these various elements enables the lover of the psalms to get a grasp on the whole of the Psalter along with a fuller appreciation of each individual psalm.