[paul2748]

Make sure the distributor is in the right place. Get # 1 cylinder (front, passenger side) up on compression stroke. You can usually tell it's there by noting the exhaust and intake valve on #1 cylinder are loose (both valves are closed). This should be top dead center (TDC). Check the pointer to the timing mark on the damper. It should be on the first mark. Then check the distributor - the rotor should be pointing to #1 cylinder on the cap. This should be your starting point. Then you can advance the timing using a timing light.
Remember, the crank turns two times to the camshaft so the piston comes up to top dead center twice in one cam revolution. For timing, you have to get TDC on the compression stroke (when the valves are closed).
Also keep in mind that the damper with the marks over time can get loose and rotate, screwing up the readings. EDIT See my comments below