The answer to this question is: the earlier the better! Become an avid
reader; add a novel or a magazine once a week to your regular English
coursework. SAT reading passages are taken from literary fiction, Op-Ed
newspaper pieces, opinionated essays, and articles on natural and social
sciences. Write down any unfamiliar words, look up the definitions in a
dictionary, and learn them. A notebook can be used for this purpose. Focus on
your essay writing in your school coursework. Pay attention to those red marks
your teacher makes and think of them as useful SAT preparation feedback. Take a
timed SAT section a week from an SAT preparation book. This, by definition, will
take you less than 30 minutes, including the time it takes to correct the test.
Be aware of your strengths and weakness and stretch those mental "muscles" that
need work.
For math, review the concepts you are learning in Algebra I and II and
Geometry on a weekly basis. It is worth working ahead and cracking that Algebra
II book. Zero in the teacher's red marks, and practice the questions you get
wrong on school tests until you not only get them right, but understand exactly
how to get the right answer and why it is correct. Since time constraints are a
part of SAT test-taking, learn and practice the most time-efficient way of
solving certain problems. If you are one of those students who have a "math
block" hire a tutor early on who will work with you both on coursework and on
SAT preparation.
In short, integrate test preparation in your day-to-day schoolwork for
long-term, effective skill building.