[Damien]

You can test for a short by taking the positive battery cable off and putting a test light in series with it to the battery. With the key off you should not have any power draws. You could have a hot wire for the radio grounding on the dash.
To jump the starter, I generally use an old screwdriver to go from the battery terminal on the starter to the small terminal on the engine side of the starter. There should be at least one wire on the small terminal.