$, hotel booking sites, internet places?

what should i bring cash or cards,and what kind of cash, nz, am/ can, travellers cheques; where are best places to find internet to check emails; is it peak holiday period for new zealander over christmas ie will tourist sites/hotels be booked solid, what is cheap hotel booking site used by new zealanders-- booking family flights used up a lot of my budget so I need some tips to keep the rest of trip on budget dec 23 til mid jan. thanks