I am attempting to learn the fundamentals of how to build OS X (10.8.3) GUI applications using Xcode 4.6.2. I apologize for this long post, but I want to try to get across my current state of ignorance in the hope there might be some helpful suggestions out there. I also need to learn Objective-C, but I suspect using Interface Builder to develop GUI apps will be the more difficult step for me. I have done a lot of C and assembly programming over the years but never any OOP. I recently moved to a Mac Mini from Windows and really like it a lot. On Windows I could never face trying to learn Visual Studio and C++ etc. I am now pretty determined to learn how to produce GUI apps on the Mac but have only been at it seriously for a few weeks. (At age 67 I am a slow learner!) I have been browsing for examples and tutorials and stepping through a number of things. Most examples and tutorials I have found are from older versions of Xcode and too many are for IOS rather than for OS-X. I have the Fifth Edition of Programming in Objective-C and have on order the 4th Edition Hillegass book Cocoa Programming for Mac OS X. The Objective-C book has very little Xcode information and I hope the Hillegass book might be helpful in that area. I have a specific project in mind that I think will be useful to help me get into both Objective-C and Xcode in more detail once I get past the initial "brick wall" where I am currently stuck. I will try to describe my goal, but my terminology will probably be pretty poor. This project will have two text view objects, one to type characters into and one to display information in. I need to be "first responder" (?) so I can receive and process keyDown events and take actions by displaying something in the second text view object. I have found an example Xcode project that is very similar to what I have in mind: http://hayne.net/MacDev/TestKeyDownEvent/ but it comes from Xcode version 2.4 and I am unable to "translate" it sufficiently to duplicate the function under Xcode 4.6.2 with AppDelegate etc. I have gone through the Apple Getting Started tutorial and mechanically followed the steps to drag from the XIB objects to the AppDelegate.h file and set up the Actions and Outlets etc. but with very little understanding. If anyone can provide links to other tutorials, references etc. I will be very appreciative. An example project, built with Xcode 4.6.2 that responds to each typed character and takes some action would probably be my ideal resource since I think I could then experiment and use Xcode until I generate files with the same content and in the process hopefully come to understand the fundamentals. I have not yet found anything of this nature. My specific target project involves controlling and communicating with an external device using a USB serial port and this library: http://blog.andrewmadsen.com/ I have run the example project and it works well, but I have a long way to go before I am ready to integrate it into my own project. Thanks.