According to the New York Times (no link because subscription required):
Joel Osteen . . . the pastor of Houston's Lakewood Church, one of the nation's largest congregations, and the author of Your Best Life Now: 7 Steps to Living at Your Full Potential. has signed a book deal with Free Press, an imprint of Simon & Schuster, that publishing insiders say is potentially one of the richest for a nonfiction book and could bring the author more than $10 million.