I just started using Kaplan and I've been doing some research. One friend of mine who took the course already said the Kaplan books are a waste of time and the online material is key. I did a couple chapters in the PS book and it was more of a refresher, reminding of some concepts and problems that I forgot. I am wondering if I should stick to just the online material or read the books as well? Can someone explain how the books did or did not help and how I should use the Kaplan materials?