There are a few books at the library dealing with this subject. THey are all 4 inches thick but very informative.
I had about 6 of them in the house last month.
What I gleaned from most of them is that colleges are looking for well rounded with a bump, or passion.
So good grades, yes, but not neccessarily straight A's. Colleges would rather see some B's and C's in AP classes than straight A's in regular classes. That came straight from the U of Chicago's admission's mouth.
High SAT, yes
4 years on one team, say swimming
PADI dive certified
lifeguard---these last three show a passion for swimming
Or say 3 years on the soccer team, and then help coach or ref the parks and rec soccer team--passion for soccer
Volunteer time--this could also tie in with your passion, be the summer swim league's asst coach
Between junior and senior year make it count, do something momentous, like take a college course in something you are thinking of pursuing, There is a Criminal Justice course for 3 credit hours at Marymount UNiv, it is geared towards rising high school seniors.
Look into some summer oppurtunities--Robotics courses, What is he passionate about? Science camps, Great Books Summer camps, a college course at the comm college, Spanish 1, for instance
Host a foreign exchange student
Find a volunteer opportunity, say the Humane society, start now cleaning crates then work/volunteer for all 4 years. Work up to being the one in charge of the HUmane Society days at Petsmart or Petco.
Does the English Dept or Hist dept have a culminating project for seniors? OUrs does all 4 years, make these count. A child in our community set up a nonprofit organization for wells in Kenya, he had a 5K run and raised a lot of money.
Have him take the PSAT/NMSQT if the high school offers it to underclassmen other than juniors. It is a good indicator how you will do on teh SAT and he will get practice.
We bought the KAPLAN's SAT PREP for online with tests. It was very helpful, it pinpoints where he'll need to work more.
Talk to guidance, they should have soem idea where to go for scholarships.