Here are my recommendations to prepare car for winter/long term storage. I was in the marine industry for years and the proper winterization of boats was important. Some of my suggestions come from that experience:
1. Change the engine oil and filter prior to storage. Used oil contains chemical contaminants that can cause corrosion to internal engine parts during long periods of storage.
2. Put a fuel stabilizer in your gas tank. I recommend StarTron. It is particularly effective for preserving ethanol fuels up to 2 years. Boats and yachts often sit for long periods of time without use. Never heard of a single fuel related issue for those using StarTron. Actually, I use Startron in all my vehicles year around to prevent fuel problems from occurring. http://mystarbrite.com/startron/
3. Make sure the gas tank is 95% full when stored (leave some room for expansion when the weather gets warmer). This prevents open space in the tank that can allow condensation to form and run into the fuel under certain atmospheric conditions. A full tank greatly reduces the risk of this occurring. Some people will advise you to empty your gas tank for before storing a vehicle. Empty gas tanks will accumulate condensation and you will have water in the tank over time. I would NEVER advise anyone to store a vehicle with an empty tank UNLESS they were prepared to drain the water out before use. Very hard to do for most cars (and boats).
4. Get an intelligent battery maintainer that will keep the battery charged but automatically regulate the current to prevent overcharging. I use a CTEK Multi US 7002. Very good piece of equipment. I also leave the battery in the car. http://smartercharger.com/products/batterychargers/ctek-multi-us-7002/
5. Check the engine coolant levels. Test the coolant for proper anti-freeze protection levels. If the coolant is bad, flush the system and add new coolant.
6. Inflate the tires to the correct pressure. Use Flatstoppers to prevent flat spots on your tireshttp://www.autogeek.net/tire-supports.html
7. Chock the back wheels (I use large rubber chocks) to prevent the car from rolling. Release the emergency brake. If left on for long periods, the metallic brake pads can fuse to the rotors.
8. Wash the car and apply a good protective coat of polish.
9. A car cover to keep the dust out is OK as long as it is porous and can breath. Heavy, non-porous covers allow moisture to collect underneath and corrosion can result. This is true for both indoor and outdoor storage under a cover.
10. If you live in a damp area or store the car in a damp area. Put some No-Damp canisters in the interior to absorb any moisture that gets in. If you have a heated garage, this is not necessary.http://www.starbrite.com/category/no-damp-dehumidifier
11. If you have a rodent problem, cover the exhaust pipes to prevent the critters from building a nest inside. Rodents can also chew up wires and get into other places in the car and cause havoc. I recommend mouse/rat traps if the circumstances warrant. Another alternative is to get a garage dwelling tom cat. Your dog cannot help you with a rodent problem.
12. Once you have the car completely prepared for storage, I do not recommend starting it until spring. Boat engines do not get started during storage and they do just fine in the spring. If you feel you must then I would run the car for at least 15 - 20 minutes. If the roads are clear of snow, sand, and salt, then a 20 minute drive would be ideal.