Best Self Study for PSM II Certification.

To prepare for the PSM II I followed the recommendations on the PSM II description page (https://www.scrum.org/professional-scrum-master-ii-certification). That was enough material for me to me validate my understandings. I have not attended the classes for any of the certifications I have obtained from scrum.org. I found that the PSM II exam was less about "do you know" and more about "can you apply". You will find a lot of information and perspectives on the internet and in books.  None of them are definitive.  If you take the exam and do not get a passing score you should inspect your interpretations, re-read material you previously read and look at things from a different point of view. The exam's answers are based upon the intention of the question's subject matter and less about the actual descriptions. 

I will admit to having to take the PSM II test more than once before I could pass. The non-passing attempts helped me because it pointed out that I needed to inspect my understandings and adapt them to be more in line with the Scrum Guide's intentions. I haven't attempted the PSM III certification because honestly I don't feel like I have the necessary knowledge or real life exposure to be able to obtain it.  Plus I really don't want to get the certification unless I truly understand the material.  Just having a certification doesn't mean you are capable of doing the work. I use the certifications as a method of validating to myself that I am ready to take on the "next level". 

Good luck.