I would start by putting a little bit of oil in each cylinder and rotating the engine by hand, to help lubricate the rings and build compression . Also change the oil & filter, new spark plugs, cap rotor & points, replace the thermostat and any rubber hoses that look bad, and flush out the radiator. I also would put in some fresh gas and replace the battery if it's really old. From there I would start the car and let it run for awhile so the fluids circulate, and then drive it around the block very easily. From there I would look for any leaks or issues that might occur and then fix as necessary.