Congratulations on the profile that you've developed so far. I don't need to tell you what your profile's strong points are. But I can tell you that there are a few things that go against you if you apply to an ultra-ultra elite like H/S this year. First of all, these schools are notoriously selective (Don't underestimate the competition). Then, R3 is a killer in these schools. Then, these schools pick only a handful of limited-experience candidates (Yes, they are "youth-friendly" .. but only so much). And finally, such schools (This is true for H at least) are not reapplicant-friendly. So if you apply this year, you harm your next year's chances.
So I would say, do this (I am pretty much repeating what prasad and kryzak already said):
1. Research top schools that interest you - read about them online, visit them, talk to students, find some current MBA students / alumni (Perhaps in LinkedIn) who are from your own undergrad school / background and get some guidance from them etc.
2. Create profiles in all your top schools and go through every part of their application form. You may find some areas that they ask about where you are lacking. Use the rest of the year in solidifying yourself in those areas. For example, you may find that they ask for separate in-school and after-school extra-curriculars. And that you haven't done anything worthwhile after school.
3. Read the books written by Montauk and Paul.
4. Look at those schools' essays of this year .. and start collecting information or start working on the drafts. First and foremost, "Why MBA / Goals". Then Leadership, Mistake, Cultural shock / Outsider etc.
5. Leadership, Leadership, Leadership. Work on that, grab opportunities that let you develop / show leadership.
6. Read more about consulting / strategic consulting. Develop your case for why that interests you and that is a logical progression choice for you.
All the best! I wish I had visited GMATClub when I was 21 years old