Brodie,
Quickest way would be to half split the system. Do you have a multi-meter or know someone who has?
Easiest point to get to is the light and fuse.
See if you have a voltage supply at the light;
If you do: its most probably the light fitting (or the return).
If you don't: check the supply either side of the fuse. Unlikely the second fuse has blown but best to check.
If there's no supply at the fuse you'll need to half split the system again.
If you need any assistance let me know and i'll help where I can
