Spend some time at the public library. Let your son browse through the books and pick out several - ones for him to read on his own and ones you can read together. Encourage him to try all kinds of genres like science, historical fiction, mysteries, humor, science fiction, autobiographies, etc. Make your trips to the library an adventure!
It doesn't matter how old your son is, all kids like to be read to. Set a specific time where you can curl up with him and read or he can read to you. Make it fun - read in different voices, talk about the characters, make connections to other books or things in his life, or even act out a scene.
Also, be a role model for him - if he sees you reading, he is more than likely to pick up books himself. I suggest you both stop what you are doing and read for 15 - 20 minutes. It is a great way to unwind, and then you talk about what each of you read afterwards.
Hopefully these ideas sparked a few more. Happy Reading!
My son was the same way until very recently. I think a lot of it was that the books he could read just weren't that interesting to him. The things that seemed to help us to finally 'break through' with reading were:
1) Not reading books that were too challenging, to start. If my son needed too many prompts, he would always stop. I think he viewed himself as 'weak' if he needed a lot of help. And no self respecting boy wants to appear weak!
He also had a couple of books basically memorized, but we just let him keep 'reading' them over and over - it helped him feel like a good reader and built his confidence.
2) Once he felt more confident, and had more practice under his belt, he was self-motivated to read more exciting stuff. We move to books that were a pretty challenging, but that he REALLY wanted to read. For my guy: Captain Underpants was the ticket. We would take turns reading these at first. Be sure to budget LOTS of time for looking at the pictures with this particular series... I'd just give him any word he didn't know straight away so we could keep the momentum of the story going. Eventually, he either memorized or could sound out the words he didn't know.
He started learning syllables at about this time too, and it really seemed to help him figure out big words - it was pretty amazing at times.
Good luck! Once my son's reading got going, it took off very quickly - and I get the sense that that's pretty common in 1st and 2nd grade. I will say that with my boy, its definitely a lot harder to find interesting reading material than it was with my older girl.