Wires make my head hurt. Need advice.

[rhr1956]

I need to rewire my mast. Currently it only has a steaming light. I would like to add spreader lights and a masthead light. The mast is deck stepped with wiring internal. There are no external plugs or connections. There are currently two wires that power the steaming light which is disconnected by a two pin marine plug for mast removal. There are two more pairs that are stubbed out from the cabin top and terminated. The breaker panel lists the extra pairs as "spreader light" and "spare 1". The breaker panel also has a "spare 2" but I'm not sure where it's wire is run. I'm mechanically inclined but electrical stuff confounds me. Any recommendations for tackling the project would be must appreciated. The mast is currently in the backyard on saw horses and I'm rearing to go.