Do you need information on using Xcode to write standard C++ programs (example: you're taking a C++ programming course) or do you need information on writing Mac applications in C++?
If you need information on using Xcode to write standard C++ programs, I have an article that walks you through the creation of a simple C++ program in Xcode.
I don't know of any tutorials for writing Mac applications in C++. You either have to use Cocoa, writing your user interface code in Objective C and your other code in C++, or you have to learn Carbon. There are no up-to-date books in Carbon.
If you are going to write mac OS X only applications Objective-C and the Cocoa framework using XCode is probably the way to go. Cocoa Framework code won't port to other platforms.
Have said that O'Reilly Have a book "learning Cocoa" which is pretty good. There is also a free apple getting started guide which is probably a good place to start before you spend any cash on a book. http://developer.apple.com/referencelibrary/GettingStarted/GS_Cocoa/index.html
It all depends what you want type of app you want to build... in the end.
If you are going to write mac OS X only applications Objective-C and the Cocoa framework using XCode is probably the way to go. Cocoa Framework code won't port to other platforms.
Have said that O'Reilly Have a book "learning Cocoa" which is pretty good. There is also a free apple getting started guide which is probably a good place to start before you spend any cash on a book. http://developer.apple.com/referencelibrary/GettingStarted/GS_Cocoa/index.html
It all depends what you want type of app you want to build... in the end.