Willkommen! Since you are going over the Christmas-New Year's holiday time, I recommend you get a hotel reservation right away! You can book a hotel through NCL if you wish, adding it to your reservation; the advantage of that is that they will have a desk in that hotel where you can check your bags, etc. for the cruise, instead of waiting until you get to the dock.
There are many, many hotels in Waikiki, not so many near the port itself. If you want something very special, and don't mind spending more money, the Moana Surfrider or the Royal Hawaiian are beautiful, the two oldest hotels in the area (but nicely kept up). Midrange chains include some of the Outrigger hotels; the Ohana and ResortQuest hotel chains will be more "budget" (lower price), many of them not right along the beach. The Princess Kaiulani is across Kalakaua Ave. (a busy street, but lots of pedestrian crossings) from the beach, less expensive than staying on the beach itself, but a nice hotel. Hilton Hawaiian Village is a beautiful spot as well.
Fanning Island is relatively undeveloped, and is quite flat. The people there will be happy to have cruise visitors, for the most part, too. NCL bills it as "Hawaii the way it used to be" - sort of true, in a way, I guess.
Norwegian Wind is one of their older ships by now, and was one of the first ones to be "stretched" - a new section being added in the middle. As a result, you can't walk from bow to stern on just one deck, but will have to use stairs or elevators in a few places. She's a pretty ship, though. You probably know that NCL has "freestyle" cruising - there are no assigned dining times or tables, but instead it's like a restaurant - you choose where you want to eat and make a reservation for the time you want each night. (Make reservations early in the cruise for the popular restaurants!) No formal wear required, though you can dress up if you want to.
Have a wonderful time!