Thanks guys.
Niraj raises a good point in that I can be a terrible perfectionist when is comes to games like this, to the point that it ruins the experience. I have a hard time playing Advance Wars games without restarting levels numerous times until I can get the highest rankings. I will make a point of not doing that going in to this. In fact, this post has made me decide in advance to play on Casual Mode.
One more question: Any suggestions as to what difficult I should choose as someone new to the franchise? I don't want to get in over my head but I don't want to get caught in one of Nintendo's no-challenge difficulty levels either.
If you're going to play Casual, Hard is probably better for you. Classic Normal is also no cakewalk if you don't grind.