So yes, season. If you don't, they'll rust quicker'n you can say, um, "That pan is rusting again."
Maria, while seasoning is good because it looks good and does
help protect cast iron from rusting. It is not true that if you don't season it, it will rust. A nice oil will keep it from rusting. In my opinion, I think the way I do it serves the interest of those who like cast iron dark, but yet don't want to season a piece because they ain't gonna be cooking with it, but if they change their mind some time, they can. I strip the piece down naked, either electro or lye, and then wash it down good with soap and hot water, and steel wool, and then dry it by towel and put it in a preheated oven at 325 for about an hour, then I take it out and put mineral oil on it, it smokes and it darkens it up too, and keeps it from rusting and makes it look real good and you only gotta do it once. Then if you wanna use it to cook with, wash the mineral oil off with soap and hot water, and then season to suit yourself.