If you're remotely serious about this, get a book. Online tutorials and video tutorials won't go deep enough. And when you're into your first serious project, you'll need to have that deep enough understanding, else you'll spend all your time asking questions on forums that you would have already known the answers to. (Not that I'm saying you shouldn't ask question on forums.)
For your learning style, which I'm picking up from your posts, I don't think Kochan would be a good fit for you.
Perhaps
Clair (2010) Learn Objective-C 2.0 : a hands-on guide to Objective-C for Mac and iOS developers. Addison-Wesley Professional. Be sure to do all the exercises and take the time to understand what you're reading. Don't rush.
Or perhaps
Istead (2010) Beginning Mac programming : develop with Objective-C and Cocoa. Pragmatic Bookshelf. Personally, I like the style of the Progmatic Programmer's books.
Neither of these will teach you Cocoa (at all or extensively), but you will have an a good foundation in Objective-C and the Foundation framework. So you could then move to Hillegass to learn Cocoa GUI programming.