You can get a spark tester from an auto parts store. It looks kind of like a spark plug, but has a clip on the end where the threads would be, that gets clipped to the engine, and the other end gets the plug wire connected to it.
Then you crank the engine and look for a spark in the end with the clip on it. The spark should be blueish white, and jump the gap easily. You can do this test with the coil wire, and the spark plug wire.
Just be sure there's no fuel leaks around the area where the tester is clipped, as open sparks do not go well with fuel....
