A good way of learning Cocos2d-x is to convert an existing Cocos2d game. One that we chose was the tweeump game. The code for this game is at: https://code.google.com/p/tweejump-cocos2dx/
Some discussion about the development is located on the Cocos2d-x forums at: http://www.cocos2d-x.org/boards/6/topics/1652
The main difficulty in doing this port was the the original tweejump located at https://github.com/dvydra/tweejump was based on an older cocos2d.
The Objective C was that not difficult to port to C++ and the rules of translating Objective C to C++ posted here http://www.cocos2d-x.org/projects/cocos2d-x/wiki/Rules_of_translating_objc_to_cpp provided some guidance.
Keep an eye on the repository for the Tweejump as updates to the code will be made until it is a good solid example of a game using Cocos2D-x with C++.