My exam date for the Security+ exam is coming up soon in a couple of days, and the two books which I found the most accessible and useful were the security+ book for the SY0-401 exam by Emmett Dulaney and this book. Though this particular edition is for the previous version (SY0-301),it complemented the former book incredibly well and would recommend this only as a supplement.
I took this as part of an online course through Cengage. The textbook is well structured and provides a breadth overview of Security concerns. The labs had a tendency to overly rehash the material or go completely off target from the chapter material it is included in.