Depending on how much time you have, I'd recommend reading only one chapter a day and really trying to take it in. Then later in the day (because these chapters are pretty short), or the second day, I'd reread the same chapter while making notes and highlighting and take the quiz at the end. Then brush up anything you still don't get 100% with YouTube videos.
Memorizing AP cliffs and doing bio destroyer will land you in 20+ on bio on the DAT. In my experience, KBB is pretty useless, but good for reading the same info in a different way for memorizing. The practice exams are eh. Good practice for content I guess. Good luck!