They will be in your cabin. If not ask the cabin steward
Make sure you bring them back or you will charged.
SS Norway (12 times) '85 - '97; Radiance OS 06/01; Island Princess 11/04, Grand Princess 11/04/05, Golden Princess 7/21/06, Golden Princess 2/24/07, Explorer of the Seas 12/23/07, Island Princess 11/15/08
They should be in your cabin when you board. If you need more, just ask your cabin steward. Also, when used, I put them on the bathroom floor just like used bath towels. Try to make sure you do this in the evening before you go to dinner. You will need dry towels for the next day.