Mine sits from September to May. And all I do is make sure the tirepressure is right. And fill it up with gas. And clean the thing. I know some says that you should give the tyres extra air in it to prevent flatspots, but i don't.
I've heard that with this kind of tires that we use on our cars, porsche and such. They are so good, that you are not going to get flatspots. It happens to normal tires. BUT ONLY A RUMOUR!
Best regards
Kim