If you're taking the SAT soon, you can start by preparing today with questions from real SATs.  Download a real, full-length SAT practice test, watch Sal work through real SAT problems, and get even more practice using their interactive exercises, which feature tons of previously-unreleased problems from real SATs grouped by topic and difficulty level.  If you feel like you need to brush up on fundamentals, check out the Algebra mission, which will help you master core concepts covered on the SAT, in college, and beyond at your own pace.