L.H.
S.,
I love anything written by EB White, Charlotte's Web, Stuart Little, The Trumpet of the Swan. The Boxcar Children is a series that's highly regarded in Christian circles and is a series that you could build on. My son enjoyed the Magic Treehouse series but some circles don't like it because magic is involved. I think they're great and educational. My son learned a lot from those books.
You could also go to your local library and ask. Most librarians are very happy to assist parents in their quest to help a child love to read. Also if you have any Christian book stores locally they generally have books for all ages.
Good luck in your search. I don't know if you do this or not but we always have a read aloud going in our home (usually 2-3). Right now I am reading the Indian In The Cupboard series and my family is really enjoying it. Maybe you can have a great book going with your son too.
Happy Thanksgiving!
L.