step 2 should be WinBasedAppAppDelegate.m

no the header file.

Yes, you are so right.

And I found some errs as following so far:

P.47 - When the MinWindow.xib --> should be MainWindow.xib
P.66 - the code of -(void)dealloc section
[nameTextField release]; --> should be normal, not BOLD.
[secretPin release]; --> should be BOLD

P.70 - the filenames after FIGURE 3-34 were typo --> they should be
BasicUIAppDelegate.h (middle the page)
BasicUIAppDelegate.m (last paragraph of the page)