A few weeks back I was at MacWorld where I talked to the people at APRESS to see what books they may have on CoreData. They had one that seemed to be pretty good and I have picked it up. The book is called Pro Core Data for iOS: Data Access and Persistence Engine for iPhone, iPad, and iPod touch by MIchael Privat and Robert Wamer. While the book only covers thru iOS4, I figure it may have a better structure and approach for understanding the basics of CoreData.
I plan on spending time over the next few months going thru this book…and will provide some feedback here on what I think of it, and if it helps me get passed my mental block on CoreData.