If possible, salt the chicken at least an hour ahead of time (or even overnight - leave it in the fridge). Pat the chicken dry with paper towel and generously season the inside and outside with salt. Do this at least 15 minutes in advance if you can't do it ahead of time.
Preheat oven to 425F and move the rack to the middle of the oven. Place your cast iron skillet in the oven so it warms up (I do this as soon as I start preheating the oven).
Pat the chicken dry again. Coat it in 1 tablespoon of the olive oil. Add some pepper and seasoning/rub if you're using one.
Once the oven is hot, take the skillet out and add the remaining olive oil. Move it around the inside of the pan so it's coated.
Place the chicken in the middle of the skillet, breast side up. Return the skillet to the oven and roast for 45 minutes for a 3-lb. bird (see blog post for timing guidelines for other size chickens). I strongly suggest placing the skillet on a large baking sheet to catch some of the splatter (I did not do this and had to clean my oven).
If the skin hasn't browned enough, broil it for a few minutes (watch it carefully so it doesn't burn).
Let the chicken rest for 10-15 minutes before carving.