I always change the oil before i park it, and i also change the plugs and lights. Plus i always start it and ride it around a bit about 2x a month, weather permitting. I just like for my bike to be ready to ride, no problems, in the springtime. I live in NH.
I have a Kawasaki Vulcan and the only thing i usually ever do is get it serviced before winter and after winter (then throughout the spring, summer and fall when it acts weird)