Check all radiators for proper antifreeze protection soon. You should change antifreeze every 2 or 3 years so as to keep its rust protection.
When you mow for the last time this year be sure to winterize the mower. Add some StaBil to the gas and run the motor long enough to get it in the carburetor before shutting it off. I like my mower deck's underside to be scraped, wire brushed and painted with Rustoleum to prevent rust from eating on the deck all winter. Take the battery out and keep in a safe warm place. You can slip the battery in to your wife's closet and set it on a block of wood while she scraping the mower deck. I've found if you cover the battery up with some summer clothes, she shouldn't even find out about it...unless of course, the acid eats a hole in her new blouse.
The 2 cycle motors on weed whips, blowers, edgers, etc. should be okay without StaBil as the oil in the gas slows its evaporation. It's also a good time to have the blades sharpened for next year. I prefer to wait until spring to change the oil and filters so any condensation from the winter will also be drained out.
Don't forget to drain the water out of your boat motors. Used washing machines and dishwashers stored in the garage should be drained also, or you'll be finding them a new home in the landfill next spring.