98 Honda Shadow rear-end electrical problem.?

I just bought this bike and its my first, so if i sound stupid i apologize in the beginning... Its a 1998 Honda Shadow 1100, when i bought it i didnt even think about checking the rear lights, but when i got it home i saw the problem. When you turn your key in the on position your headlight come on, but my rear light wont. BUT when i push the front brakes the license plate light and the brake lights come on... It seem that he wired the rear lights to the brakes only. So my question is how do i rewire it right? Do i run the wire to the fuse box or run it to the head light? Im sorry for such a stupid question, but im really confused.