First you have to find your area of interest. Doing general volunteer work is almost never helpful for admission to the Top 100 colleges.
Summertime is one of the best times for high school students. Daily routine and structured days give way to sunshine and mostly empty calendars. Apart from taking a much-needed break from academics, students should use their summers to expand on their interests.
Success in college looks different for everybody.
You go to college to learn. That's the whole point of it. After having completed my freshman year, however, I realized that you learn just as much outside the classroom as you do inside it. And, believe me, these lessons will bruise you and break you just as much as the exams and labs do.