What dictates whether or not you need that big 1 meg parallel resistor with your clock? When I look for oscillators on Digikey, the datasheet mentions nothing about it. On the Uno it's there, but on the Atmel Datasheet, it mentions nothing of it.
Gibson486:
What dictates whether or not you need that big 1 meg parallel resistor with your clock?
You don't need it. An appropriate resistor is built-in. Start on page 12...