Cocos2D v3.1 includes a new rendering engine with vastly improved support for shaders. This project is intended as both a beginner introduction to writing shaders for Cocos2D as well as a "cook book" of ideas to make your own.
You'll want to perform a recursive checkout of the project since the project has a submodule for Cocos2D. Change directory (cd) to your project directory and then perform a recursive checkout. The GitHub for Mac client might do this part for you, I'm not sure. The CLI tools do not.
cd myProjectsDirectory/orWhatever git clone --recursive https://github.com/slembcke/Cocos2DShaderCookbook.git
Then you'll have a nice fresh checkout named Cocos2DShaderCookbook in the current directory.
Each of the examples is fairly self contained and includes an explanation to go along with the code. If you've never written a shader before, you'll want to start at the beginning since the explanations are meant to be read in order.
Good luck!