At the beginning of every month, you ought to be checking christianaudio.com to see which audiobook they’re offering for free. I would say that at least half the time, it’s a book I want hear. All you have to do to download the book is give them your email address and agree to be on their mailing list (don’t worry, they don’t inundate you with emails).
This month, they’re offering Everyone’s a Theologian: An Introduction to Systematic Theology by R.C. Sproul. Here’s the description:
Many people react negatively to the word theology, believing that it involves dry, fruitless arguments about minute points of doctrine. Yet as Dr. R.C. Sproul argues, everyone is a theologian. Any time we think about a teaching of the Bible and strive to understand it, we are engaging in theology. Therefore, it is important that we put the Bible's varied teachings together in a systematic fashion, using proper, time-tested methods of interpretation so as to arrive at a theology that is founded on truth. That is precisely what Dr. Sproul does in Everyone's a Theologian: An Introduction to Systematic Theology. This book is anything but a dry discussion of minute points of doctrine. Dr. Sproul, demonstrating his trademark ability to make complex subjects easy to understand, surveys the basic truths of the Christian faith, reminding us once more of what God is like and of what He has done for His people in this world and the next.
The nice thing about christianaudio.com is that along with the free book, they offer similar books at a discount. This month, there are six more audiobooks by R.C. Sproul discounted to only $4.98, including The Holiness of God (the book I recommend more often than any other to people interested in apologetics), Defending Your Faith: An Introduction to Apologetics, and The Consequences of Ideas.