Psalms by The Navigators

I found this book a very useful study guide,.It starts out with a brief introduction to Psalms and asks the question does prayer make a difference? after using this book you will hopefully come away with the knowledge of how to pray more effectively.
In the 10 lessons i found things that i had not seen before so this book would be good for someone who is just starting out on their spiritual walk with God.It's a compact book filled with useful information.