Do you preheat casserole dishes such as you would with a dutch oven. Maybe kind of dumb question.....but just not sure
You mean for baking bread inside them?
If so, then yes, you should also preheat corningware casserole dishes. (Caveat: some people have had success without preheating their dutch ovens - search "no preheat method" here on TFL).
not preheated. It can shatter when cold dough makes contact to the hot dish. Let dough rise in the dish and place into a cold or hot oven to bake with or without the lid. Use parchment or butter and dust (crumb or seed) the dish before placing dough in it.