SAT/PSAT practice and book help

Does anyone know the top books I can utilize to increase my SAT scores significantly? I’m scoring in each section low 600s and high 500s, and I really need to improve fast for the PSAT in October, and sat in march/may. Any tips for books? I have the collegeboard one, but I heard it’s not very analytical in terms of why questions are correct or not, and their tests are online, too. I’ve been hearing good reviews regarding Barron’s PSAT/NMSQT 1520 Aiming for National Merit.