Only things I do to my bikes:

About two or three tanks prior to my wild guess as to winterization date, I start avoiding E-10 with the idea not having much in the tank for winter. I also start using Sta-Bil, even though I have seen no difference whether I use it or not (the red Sta-Bil makes the exhaust smell a little different). Come Winterization Day, I get the tank as full as I can (fill it at the station three miles from home), having made sure to drive the bike at least ten miles or so to make sure it is hot. I remove the battery and drain the carburetor. I make sure the tires are properly inflated (maybe a couple psi extra). The bike(s) then go onto a motorcycle trailer so they don't take up any more space than the trailer already does. That's it. I change oil on mileage, not time. The trailer gets parked under cover. If the batteries are fillable, I do so, and every month or two put them on a maintainer for a day or two. Come Spring, I remove the bikes from the trailer, check the tires and oil, put the petcock in Prime (not applicable to the 250 Ninja), install the battery, put the petcock back to ON, and the bike starts up just as if I had ridden it the day before. Winter storage is typically about six months, from sometime in October until sometime in April.

i go out to the shed and fire er up every couple weeks this will be the 6th winter..
low teens coldest so far

One of the few good things about living in middle Georgia is that you can ride all winter. Lots of days are too cold,... but,... there are lots of days even in January when it'll get up into the 50s.  Winterization is not necessary for my bikes, but I do put sta-bil in the tanks of the lawn equipment in October and let the machines run for a few minutes before shutting them off the the season.  Also, for those of you with pressure washers, make sure to always put in some protectant like Briggs and Stratton Pump Saver 6039.

reading the op gave me the feeling: "I must be lazy"
All I do is add 2 ounces of 2-stroke oil to the gas, "Stabil" in gas according to directions, ride enough to get the stabil into the carb bowl, and put a 1/2 amp trickle charger on the Battery. (batt maintainer)..
Be careful the charger doesn't boil the water out of the battery

I've had mine since 2001, never done anything but park it, and never had any problem starting it right back up every spring.

Dave wrote on 12/17/12 at 05:06:09:

4 months anyway.

Five bikes.  Never had any problems with any.  Fill tank with "good" gas.  No ethanol......Use stabil......run it for at least five minutes with Stabil in it.  Close petcock.  Drain carburetors.  If fuel injected you are done.  Put rags in exhaust outlets to prevent moisture build up.  Fill all tires to recommended pressures.  Dirt bikes go up on stands.  Road bike tires are parked on carpet remnants.  Bikes are covered and kept in a non-heated garage.  They get below zero temperatures every winter.  If you have radiators on any of them make sure your antifreeze is good for -20.  Batteries go inside house and are rotated on a "smart" charger all winter long.  I never let the batteries get very low and have had a lot of success with my batteries.  I usually start them in the spring with the old oil and warm them up and give them all a fresh oil change before the riding season.