Checklist of things to do -- IN ORDER:
1) Find a place to store it, get the tools you'll need
- Sheltered from the elements, away from chemical fumes and ozone.
- Get the chemicals you need -- gas stabilizer, any cleaning supplies.
2) Run the bike, fill the tank, stabilize the gas
- Take the bike out for a ride, and swing by a gas station on your way home.
3) Change the oil
- Do this while the engine is still hot -- it gets more junk out.
4) Put bike on stands
- If you can, take the weight off the tires.
5) Spray fogging oil in cylinder(s)
- Used to keep the rings and cylinder walls from rusting.
6) Cover intake/exhaust with bags
- While the bike is warm, cover the air box snorkels and exhaust pipe.
) Final fuel system checks
- If your bike has one, switch the petcock off.
8) Remove and charge the battery
- Take the battery out of the bike for charging.
9) Wash, dry, and wax dry the bike
- Wash and wax the bike. Get all the corrosive road salt and chemicals off it.
10) Protect the bike's exposed metal
- Spray the bike's exposed metal parts (but not the brakes!!) to prevent rust/corrosion.
11) Lock it up
- Lock it up so it doesn't get stolen!
12) Cover It
- Cover the bike with a breathable material that will keep dust off.
Lastly, thanks for your service, stay safe, come back!
Source:
http://www.clarity.net/~adam/winter-storage.html