Having learnt Cocoa myself in the last year (and spent some time trawling the internet for tutorials like you're doing), I found there's really no substitute for getting your hands on one good introductionary book. It might cost something, but the time it'll save you will be worth it. Most of what I found online was either far too brief, outdated, or went into too much depth. In general, Apple's tutorials fall into the last category. Better for improving your existing understanding rather than learning it for the first time
Working through a few tutorials structured so that each builds on the last will get you to a stage where you can dive in and understand Apple's docs and the more in-depth tutorials. Instead of learning what everything does in unnecessary detail, you'll get the broad outline that helps the rest make sense.
I found this one extremely helpful:
http://www.amazon.com/Learn-Cocoa-Mac-Jack-Nutting/dp/1430218592
If you're going to go it alone, it helps to know where to start. I'd suggest learning in roughly this order:
- Basic structure of a cocoa application (what an application delegate is, and the methods you can implement to make stuff happen on load/quit/etc).
- Get a feel for how the more simple controls you can add in IB work. Learn about actions and IB Outlets.
- Cocoa Bindings. You'll learn a lot of Cocoa's more distinctive concepts, like KVO and KVC in the process of learning this.
- If you're interested in ever saving/loading data, or having undo support, Core Data is definitely worth learning.
... and then you've probably got enough of a grounding to choose where to go next.
Have fun!