I was searching for the 2011-2012 SAT Practice Test explanations till I hit up on this guy. He put videos on how to do SAT Grammar/Math, specifically.
He has 30 videos, on the the 30 grammar rules you need to know for SAT Writing. Plus other dozens of videos on SAT Math.
CAUSE SAT WRITING GRAMMAR RULES ARE BORING WHEN READING IT. WAY MORE FUN AND TOLERABLE when watching videos.
He's really helpful, check him out waystoimprove's channel - YouTube