Why does your son want to play? Does he like rock music? If so, I would suggest getting a cheap, but decent electric like a Fender Squire Strat. (used. of course) Then he can start playing power chords, which are fairly easy and sound like he's playing real rock. Most people seem start off w/ an acoustic, learning traditional songs like 'Michael, row your boat ashore' and such, but if the kid wants to rock he'll be really bored w/ this approach.
I started playing at age 47 with this method. I can play hard rock rhythm guitar fairly well now. I stink at finger style acoustic folk. I want to learn it, but as of now I can have fun jammin' w/ my wanna be musican friends on classic rock stuff.
My lady friend's son is 12 and he's basically doing the same thing. Because he can play the stuff he likes, he's really motivated to practice.
Just MHO of course.
BTW: if you go electric, you can't beat the Roland Cube amps. Cheap, sound decent, are bombproof, and have a headphone output for everyone else's sanity. I have a nice tube amp, but I still love my little Cube 30.
