When using fresh corn in place of canned or frozed, should I cook the corn first? I have a couple recipes that call for frozen or canned corn.  If I want to use fresh corn instead, should it be cooked first or will it cook with the rest of the ingredients (like a casserole for example)?
Good question! Corn is very versatile. I've found that fresh and frozen whole kernel corn are very interchangeable when used in casseroles. Most casseroles cook long enough that you could use either without making any adjustments.

However, canned corn is a different animal. Because it is more processed I would use it in recipes that call for it but I would not consider it a substitute for fresh or frozen.