When putting your bike away for the winter, you will want to consider using fogging oil. This could be just a quickie ten minute job, or, depending on how your bike's engine is set up, a couple of hours. You may have to remove your bikes actual gas tank, oil cooler or radiator in order to find your spark plugs.
First thing you will want to do is get the muck and dirt out of the spark plug holes. You can buy those air compressor cans for just such a job, and you will find that this works wonders! If you visit your local bike shop, you should be able to find some fogging oil to purchase. If you absolutely can not find any, even after you ask the clerk, you can use some motor oil or WD40 in lieu of fogging oil, but fogging oil works best in order to get your cylinder walls well lubricated. Use no more than one teaspoon per cylinder. In the case that you are unable to remove the spark plugs you can take off the carburetors and spray the oil in through your bike's intakes. Be sure to put your bike into top gear, and spin your bike's engine by rotating the back wheel slowly approximately ten or fifteen times. If this is not possible, the fogging oil will work as well. If not, use your motor that is left over or the WD40.
The spark plugs should go back into place now. It's your choice put just a tiny bit of anti-seize on them also, so that your threads are protected.
Now put your bike back into the neutral position; perhaps you will need to spin the rear wheel once again so that your transmission shifts correctly on the bike.
If all goes well, your bike will be well on its way to being properly winterized.