Lots of good responses above. And everyone's situation is different. It's not too early.
The biggest challenge is how to engage your son in a process to actually think about his future to where he makes his choices. It's also a process that exposes a kid to realities; financial, ability, desires and necessary effort.
I remember the 14U travel coach asking the kids for a top ten list of schools they wanted to go to. And what a struggle it was for my son to think in those terms.