Tips for an iOS developer to learn Mac programming?

As Apple announces the Mac App Store, I'm going to learn Mac programming. I am typically one of those who read the Beginning iPhone 3 Development book before the Cocoa Programming for Mac OS X book. The reason I bought a MacBook was due开发者_如何转开发 to the fact that Xcode runs only on OS X. So, what's your tips for an existing iOS programmer who is also a Mac OS newbie? Thanks!

• one tip for one answer please (as community wiki)

Highly recommend Cocoa Programming for Mac OSX by Aaron Hillegass .
This is a great starting point,as you are already an iOS programmer,it wouldn't be tough.

Have a look at MacRuby. Makes it a doddle to throw together quick prototypes!

Learn and use the available preprocessor macros to share code between your model components on iOS and Mac platforms.

Its a lot like iOS programming except that resources such as RAM, the processor, drive space, and threads are abundant. It feels boundless in comparison.

If you developed for the iOS platform already, you are probably familiar to tools like Interface Builder and Xcode. My advice would be to jump right into developing some small applications. Just try out some stuff, it basically works the same as on iOS.