Look it over for cracks, how well the lid seals, if it's Spanish cedar lined. Look for evidence of mold or mildew. If it looks decent and doesn't cost that much then I'd go ahead and lightly sand it and apply a quality stain (not the stain/poly mix). Usually 2 coats are enough, then follow up with a coat of poly to protect the finish.
Even if there is no evidence of mold or mildew I'd wipe it out with a neutral grain spirit such as vodka or everclear and let it dry on it's own.

Then check out http://www.cigarbum.com/forum/cigar-...idor-1205.html and follow the instructions. If you have any issues with sealing there are ways to address this (weather stripping) to get a tight seal.