Oooh! Guitars! My favorite!
I'll assume you're looking for something reletively cheap, so I'd look into:
Ibanez
Takamine
Fender
Washburn
Applause
Peavey
All make decent, playable acoustics under $200. Chances are, your local stores will carry most of these brands.
If not, then check:
www.musiciansfriend.com
I've ordered from them many times and I've always had excellent service.
Do you play or have a teacher set up for him? If not, I can help get him started with some online lessons and links to some websites that I've found to be helpful. If he needs one on one help, I'm always online and willing to help. I used to give guitar lessons to a couples of kids here in NP. Here soon I am going to make a video lesson on Ultimate-Guitar.com covering the basic open chords, moveable barre chords and powerchords to help get beginners started. Alot of the online lessons can be overwhelming when theory buffs try to cram in all the fancy stuff, like how and why chords are formed, which is important, but is alot for beginners to take in, especially when they don't even know how to form simple chords yet.