Read with him.
Get him a magazine subscription.
Let him get his own library card and pick out what he wants.
Check out some books on CD for him to listen to.
Check out Between the Lions and Super Why DVDs to watch.
Read a book together and then watch the movie and compare them.
Our school has a book club for kids; maybe check with yours to see if they do too?
Some fun websites for him to play on:
Starfall.com
funbrain.com
and many others I'm sure.
Check out storytimes and other programs at your library.
My son loved the Magic Tree House, Spiderwick, Stink, Captain Underpants and Diary of a Wimpy Kid series. He has read every book in all of them and will still re-read some of those books.
I also make sure my kids have a book in their backpack or their desk, so they know they have something they are interested in to read during "down time" at school.
Keep encouraging it and keep reading with him, he is sure to love that!