Some basic information to get you started:
The US application takes into consideration your last 4 years of high school. This is a key difference to Australia or New Zealand and a little more intense than the UK which only looks at your last 3 years.
Essay planning needs to begin 2 years before you start applying as a minimum. The essays require highly introspective pieces of writing. These essays are not job applications - they are creative writing pieces expressing intricate aspects of your personality and background. Because they don’t simply regurgitate achievements, they take a lot longer to write and often focus on very niche experiences. Here’s an example of the essay I wrote which was featured in Business Insider which helped me gain admission into every elite US university I applied for: http://www.businessinsider.com.au/this-guy-got-into-five-ivy-league-schools-and-started-a-82-million-consulting-business-heres-how-he-did-it-2016-5
You should start planning for what teachers might write your references ideally 2 years before but the most important thing is that you’re a strong, high achieving student and good references typically follow. Most international teachers are unfamiliar with what a good US reference looks like so it is usually critical to consult an expert. We provide teachers sample reference letters illustrating what a strong US reference looks like and help candidates isolate what specific points of their candidacy they should be really emphasizing in references.
The first step is to prepare a list of all your academic scores to date, your extra-curriculars and leadership activities. From there, I recommend sending them through to Victor or another member of the team at Crimson for a comprehensive assessment of your candidacy to assess where you stand up relative to your country and what your game plan should be for the next few years.
Applying in 2017 given you are only starting now will require quite a rush but is very doable as long as you have a clear strategy and jump on this immediately.