FRM Books vs. Readings from Study Guide

Hi, I’m new here. I planned to take the FRM Part 1 exam by the end of this year but due to some unforeseen circumstances I have planned to appear in May '18.

Before getting started on preparation and study schedules I would like to know which is the best between Official FRM Part I books sold by GARP and the Reading List provided in the Study Guide, or is there any difference between the two?

Thanks.