peaches, It's well worth a couple years of his life, then he might be ready for college, I guess they still have a college fund thing that would help him.
As for as which branch, I lean toward the marine corps, but i'm a little partial to them
just try to pick a mos that he's excited about, he'll do much better in it.
Plus maybe he'll see part of the world
Good luck in whatever you and him decide