Jens Alfke's coding suggestions
Jens Alfke (one of the famous Apple engineers who used to work on the original "classic" MacOS, and fellow moose fan) is dishing out Uncle Jens's coding tips. A great read on coding style, comments and editor tricks (and yes, it's for Cocoa and ObjC).
You may wanna set up a custom style sheet, though. Especially the comments are a bit hard to read, though they contain a bunch of interesting suggestions and corrections (Yeah, I also prefer tabs to spaces for all the usual reasons, and in addition to that because it's easier to navigate them with the arrow keys, and they're bigger click targets than a series of spaces).