Hi Craig,
Sounds like you are almost there.
Your current problem seems to be with GND. The cutter should be at the same potential as your USB GND, that way when the cutter contacts the plate the digitize LED illuminates.
The resistor does not go in series with the plate. The resistor just connects your pin 10 to +5 volts, then the plate connects to pin 10 as well.
Hope this helps,
Tweakie.