Does he read well? Struggle? Find it boring? Why his dislike?
If you're positive he reads well and/or finds reading to be boring, then I'd seek out books he finds interesting. I wouldn't worry about the level, the subject (as long as it's appropriate, of course), if it's a classic or fluff. Just let him read.
If he struggles, or it's possible that's the problem, then I'd seek out books he can feel successful when reading. Don't worry about the level, just let him read and re-read to build his confidence.
For comprehension, I'd start with very basic re-telling of the story.
Some people never become avid readers, or the desire flips on later in life, just keep moving forward.