I'm preparing the SCJP exam with the almost official study book ("SCJP Sun Certified Programmer for Java 6 Exam 310-065")

I understand that Java programming is writting code that fulfills a certain high-level contract; So that Java can stay platform-independent.

However, I have trouble understanding and remembering things when it comes to highly specific SCJP items (and they are numerous)

The book stays high-level and does not provide examples of how one compiler would handle things. This is the same thing for runtime issues (JVM level): things are too much abstract for me. Rules often seems arbitrary and therefore, with no well defined purpose, are difficult to remember. Or maybe it's that sometimes I just don't get the underlying purpose.

And here is the question:

Would a JVM specification and/or some java compiler code help in preparing the SCJP? Have you had the need for such material or is the book sufficient enough? Also, please share the resources you used, apart from the book.