It's a little dated, but this helped me:
I found there were two things you needed to pass the test:
1. Command of a lot of facts about security that you have memorized
2. The ability to use those facts reason out a question that is comprehension based
When it comes to memorizing facts, I find the sort of simple practice questions in this book very valuable. I use them as a form of flashcard. When it come to using the facts to answer questions on the tests -- or solve problems in real life, it's comprehension of the facts that count.
I spent my preparation time 75-25 with 75% of the time spent reading and 25% of the time doing practice tests to help me with memorization. Other folks use mind-maps, practice tests work for me.
Don't expect the practice tests to look like the real test -- no legitimate ones do, but just use them to help you memorize the facts.
I also studied the Cloud Alliance's STAR matrix
Cloud Controls Matrix (CCM)
The CCSP All-In-One study guide is good if you don't understand something.
I just passed my CISSP on Nov 27th. I used the 11th Hr Study Guide (third gen) and the CISSP for Dummies book (most recent revision) and watched the video series from Cybrary.it (which is free and VERY good). Of course, there is no substitute for just having good hands on experience as well. Between these 4 things, I passed on my first try, in exactly 3 hours, 12 minutes (not the new adaptive test, the now "old" 6 hour 250 question test.