See here for details on a new tutorial on Core Data.
In the vein of Ruby on Rails style video presentations, you can download the narrated video (38Mb) and learn very quickly how to put together a Core Data application.
Note: for the bandwidth challenged, it is broken down into smaller pieces on the ADC site.
As someone who is largely self taught on the Cocoa side of things, it was instructive to watch another developer at work with Apple’s tools. Aside from learning about Core Data, I learnt some productivity improvements for using Interface Builder and XCode.
If you are writing Cocoa apps, this is well worth a watch!