Firstly, wash the car and apply wax. Change the oil and oil filter. If the storage area is secure, leave one window open for ventilation. Check the anti- feeze level and content.
Leave the handbrake off, and don't brake the car into its final postition- roll it there to prevent the pads sticking to the discs. Leave the car in gear and chock the wheels. Prevent the clutch from sticking by locking the pedal down (use a piece of wood)
Inflate the tyres to 45psi (if you don't remove the wheels) They will gradually deflate and this will prevent them from 'flat spotting.' It is advisable to pump up the tyres every four to six weeks. Spray WD40 under the bonnet on exposed nuts, bolts, and on any exposed electrics.
It is also a good idea to slacken off the main drive belts susch as those for the alternator and power steering. Use a light oil to lubricate the door/boot locks. Pull the windscreen wipers off the screen to prevent them sticking.
Ideally, leave the battery on a strickle charger to keep it topped up.
Don't keep too mcuh fuel in the tank, and buy a car cover to keep the dust off.
You will also need to SORN it. The form can be found here:
www.direct.gov.uk/en/motoring
When you put the car back on the road, make sure you gibe it a thorough service, for safety's sake.