How to prepare a car for storage?

just about what the others say, trickle charger, I inflate the tires to almost their maximum and put an old rug under the wheels so there is no real cold spot at the place where the tire meets the concrete what I don't do is fill her up, I have as little as possible fuel in it, so when the season starts again, I start with fresh fuel.
and I never start the car in winter, my climate is cold and moist, so by not starting it in winter I prevent that cold moist air to be sucked into the engine