Restoring Android Application state

Question

I understand that an applications state should be stored/restored in onPause/onResume, but:

1. What data should be preserved? onCreate sets up the view but should it initialise module-wide app data? or should that be left to onResume?

2. Where should the Intent that kicked off the activity be read?

3. Are onStart/onStop/onRestart ever used for anything useful?

-Frink