[[CCDirector sharedDirector] pause];
& [[CCDirector sharedDirector] resume];
will pause and resume the schedulers and actions throughout all the Sprites/Layers or any other cocos2d Nodes.
If you want to pause/resume a particular CCLayer along with children its containing,
////for pausing
[myLayer pauseSchedulerAndActions];
for(CCNode *child in myLayer.children){
[child pauseSchedulerAndActions];
}
///for resuming
[myLayer resumeSchedulerAndActions];
for(CCNode *child in myLayer.children){
[child resumeSchedulerAndActions];
}