All good advice....except for GG.
There is no need to drown the poor engine in oil unless it's parked at the bottom of the Pacific(like someone suggested).
If short term(up to 12 months) just disconnect battery, lock it up and walk away. It will be fine when you return, I have proved to myself many times over the years. For longer term, back off your rocker arms to close all valves so seal all cylinders, wrap up your carby or block throttle body to prevent dust or moisture entering intake and before starting again simply replace all fluids and you are right to go.
As for fuel going off there is a solution.
It's called STA-BIL. It is a fuel stabiliser that restores and refresh your fuel while in storage for up to 12 months at a time by simply adding one bottle (450 ml) to a full tank (65 Litres ) and it will keep away moisture and maintains octane rating while stored and ready to start. Google it!
It works. I use it all the time in my 426 Hemi Challenger that only gets started every 6 months.
