Documentation (Score 1)

I agree with most of those who have said that Objective C is easy enough to pick up in an afternoon. And in my experience, Objective C is preferable to Java for Cocoa development. And in my experence Cocoa is preferable to Carbon, not only because the Carbon featureset is a subset of the Cocoa featureset, not only because Cocoa is the native framework for OS X, but also because you can leverage the excellent development tools provided by Apple (especially Project Builder and Interface Builder). A dedicated programmer can learn how to use PB and IB and Objective C in a day or two, and proficiency in those tools will speed up your actual coding work more than enough to merit the time spent learning them.

Documentation for the development environment, as well as Carbon and Cocoa API tutorials and reference, can be found on Apple's Developer site.