there are articles on this like
http://www.edmunds.com/car-care/how-to-prep-your-car-for-long-term-storage.html
some issues:
the fuel.
long term the fuel is going to go bad,,, so is it better to drain the tank and clean out the carb, and blow out the fuel lines so this way there is no gas to go bad and turn into varnish.
on the one hand they say, if the system is full of fuel then there is no oxygen to interact and cause rust inside the tank and lines. but then the gas goes bad and everything has to be flushed out or replaced before you start the engine.
my feeling is drain all the gas out and let it sit 100% empty.
I once used fuel stabilizer and it caused more harm then good.
battery,,, my advice: take it out of the car totally and store it somewhere else, either leave it on a maintainer or just know you have to replace it later.
tires,, jack the car and put it on stands, this will save the tires from deflating and or flat spotting. this can be an issue for the front suspension leaving the A arms in the down position long term.
it might be a good idea to jack it on the frame points then put wood under the front suspension behind the tires to raise up the lower suspension so it is not 100% fully extended. i have a lowered front spring so at full decompress it does not put as much pressure as a stock spring would.
you could take the tires off and rest the spindles on some wood if it is a big concern. or some guys rest the front end on junk steel rims with bad tires.
oil change the oil and filter and give the engine one last run before you do the stuff above, some guys will pull the plugs and squirt oil into the cylinders then put the plug back in hand tight with a note to remind themselves about what they did.
rodents. might want to load the car with moth balls or other rodent repellent. some guys put steel wool into the cowl intake to prevent the mice from getting into the climate control box and then into the car.
assuming the car is inside. Recommend a light breathable car cover. this will just keep the dust off the car and keep it clean. i do not recommend a heavy car cover because it will trap moisture underneath and could cause rust issues.
the car should be at least on top of pavement, if the car is on dirt it will sink into the ground and the moisture level will be much higher in general.
outside car covers long term are a waste of money, they trap moisture and they fall apart and the wind will whip the fabric and wreck the paint.
outside you are better off leaving the car on pavement jacking it up and leaving it open the elements.
if the car leaks a car cover isn't going to help much and taping it won't last but a few weeks. at that point you want a car port or something like a temporary outdoor tent for trucks and cars.
wash and wax the car one last time use a cover for indoor storage.
there isn't anything you can do for seals drying out that will depend on environment. a heated moisture controlled storage is the best. outdoor, UV damage and dry rot is more likely.
now all this depends on how long a storage you are talking about. if the car is going to sit for 5 years or more it is a different story then 6 months to a 1 year.
I've stored my car for about a year before without doing really anything and the fuel was fine because it was indoors and had some climate control measures.
i didn't even use fuel stablizer since if had it fowl spark plugs and seals before.
longer then that i would of drained all the fuel out of the car.