The book, Portraits of Courage: A Commander in Chief's Tribute to America's Warriors, topped Amazon's best-seller list after becoming available on Tuesday. It includes 66 color portraits of veterans who served in Iraq and Afghanistan, accompanied by a personal biography of the subjects written by Bush.
The nation's 43rd president has taken up painting as a hobby since leaving office.
Proceeds from sales of the book benefit the George W. Bush Presidential Center's Military Service Initiative, which assists veterans with overcoming the physical and psychological scars from battle during their transition back into civilian life.
The exhibit based on the book opened Thursday at the George W. Bush presidential library in Dallas.
In an interview with NBC News earlier this week to promote the book, Bush was asked whether he misses being president. He said he doesn't miss the day-to-day rigors of the job, but did miss the opportunity to thank members of the military, which is how the idea for the book came about.
"People ask me, 'Do you miss being president?' The answer is not really," Bush said. "But I miss saluting people who have volunteered to wear the uniform."
Bush is not the only former president active in the publishing world. His successor, former President Barack Obama, signed a book deal this week with Penguin Random House to write a memoir of his time in office.