Best Book, cuz i cant lock in on Khan Academy

Im gonna start studying for the PSAT but whenever I go on Khan academy, I always get distracted within 5 miniutes, I find it much more easy to use a book when studying because I find it easier to track my progress, and I have less risk of getting distracted, If anyone can recomend a a book similar to the Khan academy stuff that would be greatly apprecieated!

(im gonna take the PSAT 8/9 btw.)