<p>An SAT book is usually sufficient preparation…depends on your strengths and weaknesses though. Some students can easily benefit from a tutor, and strong students can usually do just fine with very little to no preparation.</p>
<p>As an international student, I can tell you that it does require time if don’t really master English (if it’s not the case, 12th grade is way too late ). However MITer94 is right when he says that it depends on the individual. Some people are, for instance, uncapable of learning a language at home if they don’t have the possibility to go to an english-speaking country were they can practice.
Since you’re in 12th grade, it doesn’t matter to linger on that. Give yourself a shot and see for which colleges you can be a competitive applicant.</p>