I've done some delving into AppleScript but I'm interested in how difficult and long it would take to make semi-useful Mac apps.
What really good resources besides Apple Documentation?
I've done some delving into AppleScript but I'm interested in how difficult and long it would take to make semi-useful Mac apps.
What really good resources besides Apple Documentation?
"Cocoa Programming For Mac OS X" from Aaron Hillegass. Nice book that gives you an introduction into Objective C and Cocoa programming.
If you want to make widgets, they are actually little web pages, often with JavaScript.
As stesch said "Cocoa Programming For Mac OS X" is the best book available for an introduction into Cocoa and Objective-C. However if you already know python or ruby you can easily make great looking applications using their cocoabindings.
"how difficult and long it would take" depends on what you already know. If you can program in C, Java, or C++ with a good understanding of object-orientation and vague idea of how the model-view-controller design paradigm works, then you will be in good stead.
Come up with a small but interesting idea that will keep you motivated to continue learning Cocoa/Objective-C because the learning curve can be steep at the start.