Desiring God has a wealth of resources available, including many books, available HERE. The great majority are by John Piper, but some are by other authors and editors. Most of the books are available as free ebooks in multiple formats, including PDF. The others are available for purchase (some have samples available as PDFs). All the PDFs available are printable (in other words, printing is not disabled). Here is just a small selection of the books available as free ebooks. Under each title is the link to the page where you can read more about the book, and download the ebook. Unless otherwise stated, the books are by John Piper. You can find out more about Desiring God HERE.
Designed for Joy: How the Gospel Impacts Men and Women, Identity and Practice edited by Jonathan Parnell and Owen Strachan.
Don’t Waste Your Life (A Study Guide is also available from the download menu for this book.)
For the Fame of God’s Name: Essays in Honor of John Piper edited by Sam Storms and Justin Taylor.
Habits of Grace: Enjoying Jesus Through the Spiritual Disciplines by David Mathis. A Study Guide is available HERE.
The Romantic Rationalist: God, Life, and Imagination in the Work of C. S. Lewis edited by John Piper and David Mathis.
Still Not Professionals: Ten Pleas for Today’s Pastors with contributions by John Piper, Daniel L. Akin, Thabiti Anyabwile, Mike Bullmore, Sam Crabtree, Raymond C. Ortlund, R. C. Sproul, Jeff Vanderstelt, and Douglas Wilson.