Generally I agree in principal to Dmorris 1200. However, don't trust your wife with the starter trigger. I suggest the use of a piston stop which screws into the spark plug hole. You screw it in until it contacts the piston just before TDC and note the position on the harmonic balancer. Then reverse the rotation and do it again without adjusting the depth of the piston stop. Again mark the location on the balancer. The exact difference between the two marks is exactly TDC or BDC. Note that this does not take into consideration that the cam runs at half the speed of the crank, so the distributor can still be 180 degress out of phase. To determine which it is you would have to take the valve cover off to see if the intake valve is just closing for TDC.
But I don't go to that trouble. If the engine won't run one way, I pull the distributor and move it 180 degrees or move the wires and it will start.