If you are a high school student who wants to become an astronomer, the best advice is to study hard. It's important to take a lot of academic classes in high school if you want a career in any of the sciences, so make sure you fit in four years of science, math, english, and social studies. You should read magazines like Sky and Telescope or Astronomy and follow the new developments in astronomy that make it into the news. Any readings or research that you do early on can only help you later. Astronomy books are located in the 520s and Physics books are in the 530s according to the library's Dewey Decimal system.