SAT Advice (General) Post
General SAT Strategy and Additional (Non-Official) SAT Practice Tests - Ivy Global New SAT Guide, 2nd. Ed. / SAT Prep Black Book, 2nd. ed / Barron's New SAT / Barron's 6 Practice Tests for the New SAT
For additional help, consider a private tutor like me who can point you in the right direction.
Real SAT questions are of course always better to practice with, but for the new SAT, they are currently in short supply. So you should also download and take PSAT Practice Tests #1 and #2. Professional SAT tutors like me will obsessively collect every real SAT or PSAT we can find, and at the moment, there are very few of them (17 total), so of course they are especially precious.
You can also find free SAT Prep Tips on the McElroy Tutoring Blog and free SAT videos on the McElroy Tutoring YouTube page. You should also subscribe to the SAT Question of the Day.
Or, even easier (and possibly cheaper): just go to the College Board website, download those same 8 PDFs for free, and simply print them out at home. The drawbacks to this method are that the pages will be harder to organize, and that you will incur printing and paper costs.
Working with a private tutor is the very best way to maximize your score, for a variety of reasons:
1) You are given personalized attention, lessons tailored to fit your schedule, and the opportunity to discuss each question in-depth until you are fully satisfied.