One thing I did was I started reading chapter books 2-3 years above his reading level to his as bedtime reading starting at 4 or 5. One chapter a time at night.
Keep in mind that most early chapter books are often very boring books, and very easy lexile level. They are very deliberately written to be easy to read, rather than for their literary quality. They might be too easy for him. You might need to jump to books labeled for 8-12 years olds.
Another good suggestion others mentioned are longer books where each chapter is it's own story. My son loved the Encyclopedia Brown books.
