for a general tune-up? Depends on how many miles you have on it. The standard things to replace are spark plugs and plug wires (if the wires are original and you have 50,000+ miles), fuel filter, and possibly the distributor cap/rotor, if they need replacing. Also, check for cracking fluid hoses and such.

Adjusting the valves is a good idea as well. Should be done every 15,000 miles or so. Oil change, possibly the air filter, and maybe give the vacuum systems a once-over, make sure all the hoses are in good shape.