The hardest part so far has been actually taking the first steps to making the whole plan start to become real. So far in no particular order:
1. Decide When - choose what months we were going to be actually away.
2. Decide Where - once we knew our target dates we had to look at our short list of countries and work out weather wise where was going to be best (least rain, most warmth).
3. Research Airfares - skycanner.com was great here. We had to look at the best way to connect between the countries we now had decided on. What airports connected where? What days did these flights go? When was overland better than flying? Some flights only went on certain dates or certain dates were massively cheaper than others. This helped us decide how long we were going to be in each destination as well. When we were planning to go for so long every $1 saving was worth it.
4. Quit Jobs - I felt a lot more comfortable actually booking things when I had resigned as we knew what date we were going to be able to leave.
5. Book main flights in and out of NZ