Your SAT study schedule should start with a practice exam. The results of this test give you a benchmark from which to work. You can periodically take practice tests to see how well your studies go and which strategies seem to work for you.
A practice exam also gives you an idea of which areas of the exam you need to study most. For example, you may find that there’s a particular aspect of the math section that keeps you from your ideal score or that a richer vocabulary improves your score.