Re: good size drum set for beginner?
Look at the DD55 by Yamaha. It is not a drum set, but a set of electric pads with some nice built in features that will teach proper timing. I borrow one from my brother in law all the time for home practice, living room jam sessions, and church work. They are lots of fun and your son can use headphones while playing. If he shows an interest, move him up to a decent entry level drum set; Yamaha, Ludwig, Tama, and Pacific all build nice ones.
The DD55 is $239.99 from Musician's Friend, but used one's can be found on eBay. Also, even if he moves up to a set of accoustic drums he will probably always play around with the DD55 cause they really are a lot of fun.
Honestly, I would stay away from the real cheapo drum sets. Even the cheapest one's cost over $200 and the heads are terrible. A decent set of heads for a standard kit will set you back another $60 at least. Drums are not like guitars where you can go buy a Squire Strat/practice amp for $150 and have something kinda cool.
If he moves up to an accoustic set, stay away from the Zildjian ZBT entry level cymbals. Paiste and Sabian make much better entry level cymbals for the same price. For some reason Zildjian has never figured out how to make decent entry level cymbals, and I'm a Zildjian user.
Just some tips. If you really want to encourage his drumming, and the world needs more drummers, start him out on something that will teach him, and sound cool. Keep us posted.
"In a nation ruled by swine, all pigs are upwardly mobile—and the rest of us are fucked until we can put our acts together" - Hunter S. Thompson