Check the hot wire going to the coil for voltage. No voltage could indicate an open wire somewhere. If you have voltage going through the coil, remove the distributor cap and check for voltage on the breaker arm with the points open. No voltage there indicates a bad wire from the coil to the distributor or a bad coil. If you have voltage that far, try opening and closing the points. Make sure you have the correct gap in your points and that they are not burned. Your coil should pop a spark every time you open the points. Once you narrow your trouble down, it won't be that hard to find.
