A lot of colleges will release information about their course requirements, such as:
MIT (recommended):
One year of high school physics
One year of high school chemistry
One year of high school biology
Math, through calculus
Two years of a foreign language
Four years of English
Two years of history and/or social sciences
Source:http://mitadmissions.org/apply/prepare/highschool
Harvard (recommended):
The study of English for four years: close and extensive reading of the classics of the world’s literature
Four years of a single foreign language
The study of history for at least two, and preferably three years: American history, European history, and one additional advanced history course
The study of mathematics for four years, including the particular topics described
The study of science for four years: physics, chemistry, and biology, and preferably one of these at an advanced level
Frequent practice in the writing of expository prose
Source: https://college.harvard.edu/admissions/preparing-college/choosing-courses
Stanford (recommended):
English: four years, with significant emphasis on writing and literature.
Mathematics: four years, with significant emphasis on fundamental mathematical skills (algebra; trigonometry; plane, solid, and analytic geometry).
History/Social Studies: three or more years. Such courses should include the writing of essays.
Science: three or more years of laboratory science (including biology, chemistry and physics).
Foreign Language: three or more years of the same foreign language. Your study of a foreign language ought to include the development of four basic skills: reading, writing, speaking and listening comprehension.
Source: http://admission.stanford.edu/basics/selection/prepare.html
In general, highly selective colleges and universities recommend, but not require, high school classes. However, it’s beneficial to take extra classes (5 years of a FL, if possible, an extra science, 3 years of SS classes when only 2 are recommended) when possible. As long as you’re meeting the recommendations with high rigor and a high GPA, the academic part is largely covered.
All of the links I found are just a Google search away; just search “(school) high school requirements.”
Hope this helps!