My car has been sitting for about 4 months without being started (I was out of the country). What precautions and procedures should I take before starting it up?

 

oil change, make sure battery is charged, coolant level is full
do a scan of the engine, make sure no mice have eaten any wires or hoses.
may want to dump a couple of gallons of fresh gas in there, too (in the gas tank, that is).

 

I would pull the spark plugs and squirt oil in all the cylinders b4 starting just in case there are any sticking rings or pistons, maybe even try it a few revolutions by hand first... that's a bit severe but just being cautious!