Naptha -- a type of lighter fluid -- is good for removing adhesives gently from guitar finishes, even nitrocellulose lacquer. A tiny amount on a soft, cotton cloth should work.
There are a few good cleaners and polishes out there ... Virtuouso is a good choice, Petros makes a good kit for cleaning, polishing and oiling the fretboard. Collings recommends Novus polishes for its guitars. Others swear by Meguiar's car detailing products, as long as they do not contain silicone.
I have also used this system and it works well:http://www.guitarscratchremover.com
The thing to remember is, these compounds are removing scratches by taking off a small layer of the clearcoat finish, so you want to be very gentle and not go too far with it.