Use virtuoso polish and cleaner! It is the hands down BEST guitar finish cleaner and polish there ever was. I spent 20 something bucks on it at guitar center, applied it to my 1975 les paul deluxe, applied it using like a tenth of the bottle, and I haven't had to do it again since. This stuff totally cleans every piece of dirt off your finish, protects your finish from scratches (not so much dents but it helps), and most importantly makes it look beautiful. It's even blocks out UV rays too.
http://www.virtuosopolish.com/
However naphta and a polishing cloth will work wonderfully as well. In fact, virtuoso's cleaner is mostly naphta (I've made this assumption because it smells like it). Gibson recommends using naptha to clean the finish for as long as I can remember.