He seems like he wants something to get certified in before starting college. And an A+ certification is a great idea for something like this. It's a pretty easy test. Get a book off of Amazon and make sure it's for the 2009 tests, not the 2006 ones.
The certification won't get you money...very little if any. But it will deepen your knowledge in the assembly and regular maintenance of computers.
I don't even know if I would bother with getting "certified" for the A+, but I WOULD suggest learning the material for the A+ if you don't have any prior background. It will help down the road and it is at least more structured than you designing a learning plan for yourself about basic computer hardware/OS's/maintenance.