Sproul, R. C. The Holiness of God. Wheaton, Ill: Tyndale House Publishers, 1985.
Willard, Dallas. Hearing God: Developing a Conversational Relationship with God. Downers Grove, Ill: InterVarsity Press, 1999.Don't Waste Your Life.)
I enjoyed both of these book enough to order hard copies for future study and so I can lend them to others.
R. C. Sproul looks at how remarkable and holy our God really is in his rapidly-becoming-a-classic, The Holiness of God. His work, much like Piper's Desiring God or J.I. Packer's Knowing God takes the reader through an enjoyable tour of something so present but often so overlooked. There is no "how to" aspect of this book, yet it is practical in its teaching and accessible to those with little to no theological background. That being said, even the educated theologian will benefit from Sproul's observations. I highly recommend this book to anybody wanting to see God in a life changing way and be transformed by knowing God better and loving him more.
I picked up both of these book as well as a few others from ChristianAudio.com. If you're looking for audio books, ChristianAudio.com is worth checking out. Their prices are good and they run specials often. In addition, if you create a free account, you will be eligible to download their free monthly offering (where, I admit, I got both of these great books). Most books come in many different audio formats and the downloading and purchasing process is easy. ChristianAudio.com comes highly recommended too.
*I have no connection, material or otherwise to any of the books recommend in this post. I receive no financial gain or special gifts by mentioning ChristianAudio.com.