Here are a few things you can do to winterize your vehicle...
Get the right kind of oil change
Get new wiper blades
Fill up your windshield washer reservoir with windshield washer fluid
Make sure your heater and defroster are working properly
Are your battery's connections corrosion-free? Does your battery have all the water it needs?
Examine your belts and hoses for wear & tear such as cracks
Check your tire pressure
Think about switching to snow tires
Is your four-wheel drive working properly?
Got plenty of antifreeze?
Keep a full tank of gas
Keep an ice scraper in your vehicle
Make sure your spare tire has air in it
Keep jumper cables in your vehicle