SRM Study Methods

I'm debating whether to start self studying for SRM. I passed P and FM over the summer and want to sit for another. I see that people have been recommending ISLR to help supplement other sources like CA/Actex. Is there specific smaller portions of the text that is helpful, or do all 615 pages tie to some section of the exam? (I dislike reading textbooks but would be willing to in order to pass)