In recent days, several wonderful devotional books have been written on the Psalms. One notable example that I am presenting using is Tim and Kathy Keller’s, The Songs of Jesus: A Year of Daily Devotions in the Psalms. I cannot too highly recommend this resource.
Below is a link of my own thesis I wrote a few years back on how to pray the Psalms. What I have learned has been a huge blessing in my own life and ministry and I hope it will be for you. I jokingly encourage folks that, if that have insomnia, that this book will serve as a cure. Seriously, I encourage folks who are interesting in this study to start by reading chapters 1 and 8 before diving into the other chapters.
All eight chapters of my thesis on Recovering One of the Lost Tools of Christianity Spirituality: Praying the Psalms may be downloaded by clicking on this link.