If not handling a callback from the editing activity (with onActivityResult), then I'd rather put the logic you mentioned in onStart (or possibly in onRestart), since having it in onResume just seems like overkill, given that changes are only occurring after onStop.
At any rate, be familiar with the Activity lifecycle. Plus, take note of the onRestoreInstanceState and onSaveInstanceState methods, which do not appear in the pretty lifecycle diagram.
(Also, it's worth reviewing how the Notepad Tutorial handles what you're doing, though it does use a database.)