If you are looking for resources that will help you with your prayer life, below are several books that offer insights and ways to develop a more active prayer life.
The Ministry of Intercessory Prayer
by Andrew Murray
Too Busy Not to Pray
by Bill Hybels
Breakthrough Prayer
by Jim Cymbala
Book series on Prayer
by E.M. Bounds
Touch the World through Prayer
by Wesley L. Duewel
The Power of Prayer and Fasting
by Ronnie W. Floyd
A Hunger for God
book on fasting by John Piper
Praying God's Word - Breaking Free from Spiritual Strongholds
by Beth Moore
Prayer Shield - How to intercede for Pastors, Christian Leaders and Others on the Spiritual Frontlines
by C. Peter Wagner
The Prayer Life
by Andrew Murray
Prayer
by O. Hallesby
Celebration of Discipline
by Richard Foster
Out of Solitude
by Henry JM Nouen
Prayer is Invading the Impossible
by Jack Hayford
Praying for your Husband/Wife
by Stormie Omartian
Prayers Plainly Spoken
by Stanley Hauerwas
Bible-Based Prayer Power
by Ken Anderson
Prayer: A Holy Occupation
by Oswald Chambers
Becoming a Woman of Prayer: A Bible Study
by Cynthia Heald
Touching God: 52 Guidelines for Personal Prayer
by Sala, Harold J.