I am travelling to peru with my husband at the end of March to do the Inca Trail (escorted) and cannot find any useful info on what clothing to take and how much. Also is it wise to take local currency or just US Dollars?

I would advise you to take US dollars, you will be able to exchange for soles easily enough in Lima or Cuzco. As far a clothing, there's lot's of info right here on this site, check out the journals section. Also check out Lonely Planet online at lonely planet