If you are not conscious about stretched look then do this. It will work on all the devices.
pDirector->setOpenGLView(pEGLView);
CCSize frameSize = pDirector->getOpenGLView()->getFrameSize();
CCLog("%.2f and %.2f is Frame size\n",frameSize.width,frameSize.height);
pEGLView->setDesignResolutionSize(960, 640, kResolutionExactFit);
Note: The above setting is for Landscape, if you need it for portrait just reverse the values like pEGLView->setDesignResolutionSize(640, 960, kResolutionExactFit)
The thing to understand here is that everything you will design on the coordinates of 640X960 and kResolutionExactFit will fix the things as Fit to the Screen. To do this more easily you should use Coocos Builder http://cocosbuilder.com/ and design everything on a custom layout of 640X960
I am recommending double resolution (640X960) because this way Quality won't be reduced and will look crisp on all kind of devices, however the drawback of Stretched Look would be there.
If you want to consider multiple resolutions in multiple way then you have to make multiple graphics and multiple Layouts, again Cocos Builder would be the best way to do this.
i.e for iPhone 5 it would be diff and for iPad and standard 480X320 it would be diff. To do this you can put checks on frame size to select respective View.
CCSize frameSize = pDirector->getOpenGLView()->getFrameSize();