Please Ron....NOT oil or non stick spray. Both have polymers in them that will 'gunk up' the iron. Another method is to nearly fill the skillet with salt, then bake at very high heat for an hour at least. Dump out most of the salt, and rub in what's left with a half a lemon. Rinse, warm, and LIGHTLY grease with a solid fat. Vegetable fat is best as it won't go rancid as fast as meat fat.

You don't have to 'bake' the first method either...I've done it on the stove top/hob and outside on the grill. It will smoke.

Never put soap on cast iron...just rinse it out with HOT water, warm (to dry the water left in it) and lightly grease before putting it away.