My oldest boy will be turning 13 soon. I'd like to get him a good hybrid bike, maybe something from Specialized. We live near a forested area with a 2 mile long dirt trail. He also needs something he can ride to school or around the paved roads in our community.
Ideally, this bike will last him through college so I don't mind spending a bit more for a good bike. (Maybe that's wishful thinking...)
Whatever you do, if you want this bike to last him for 10 years ... you want to make sure that the saddle can move enough to accomplish this.
Get help from your LBS to decide if this is feasible and what framesize you should get.