1. I used a car bag -
http://www.autoanything.com/car-covers/69A1798A0A0.aspx - all zipped up. There are 2 examples $179 and $199. I bought the cheaper one which was fine other than it was too long. I think its worth the investment.
2. DampRid hanging bag -moisture absorber in a few places.
3. I used STA-BIL Fuel Stabilizer which is good for Ethanol-blended fuels if you have that problem.
http://www.goldeagle.com/brands/stabil/default.aspx
Of course the oil change, wash and the tire pressure.