cr0n1cHand wash with regular dish soap. The only thing is that any water left on the pan will oxodize (think Statue of Liberty green), so you have to put it over heat after you wash it to completely evaporate any water.
Also if you want the copper to stay brilliant I would recommend some copper polish - Mauviel makes a product called copperbrill that you can buy on amazon. It works very well, though it is a tad expensive, and is easy to use.