For starters it's the only airport in town. The ma...

For starters it's the only airport in town. The main airlines are Air NZ, Jetstar and Sounds.
Access is tricky and not often cheap. There is a public transport option, in the form of buses to town and you can walk, but it's a long way.
International flights are to the east coast of Australia, national flights are to Auckland in the north, Invercargill in the south and most airports in between.
Entry on the top floor, exit at the ground floor. The domestic and regional end of the terminal, despite being newly expanded, is often jampacked. The international end is usually much quieter and a better place to find a seat.
The dragons and giant eagles are cool.