Here is a very simple drawer nib file I found on the web:
http://members.blackbox.net/a/programs/
It's not much, and it certainly isn't a tutorial, but it's a start.
Better yet, try out the sheets tutorial at
www.cocoadevcentral.com (the best site on the web for newbie Cocoa programming). Many of the concepts apply (with the addition of learning about modal windows!).
I hope this helps.
What I don't find helpful is Apple's site! Once you've installed the developer's CD, you have all the documentation and examples for Cocoa programming that are on the Apple site (this isn't strictly true, but most anything that a newbie would want is a duplicate). Please, Apple, the great unwashed Cocoa newbie masses need more tutorials! It's wonderful to be able to say "Hello" and convert currency, but without lots more tutorials we are all playing an endless game of: 'I know what I want to do, I just have to figure out what name Apple gave the class and which obscure method to use - all with no guidance other than basic documentation (and sometimes even that is sorely lacking!).'