Pentlands Backpackers Hostel is located excellently if you want to be in a quiet area outside of the city center. Mt. Eden is a nice little suburb surrounded by vine-covered stone walls and quiet neighborhoods as well as some great cafes and restaurants.
There is a large supermarket, banks, and bars nearby. You can walk to the top of Mt Eden for a great view of the volcanic cones and the city in the distance. Eden Park is a fifteen-minute walk away -- very convenient if you are going to a rugby game. The city centre is also not far away, just a short drive or 1-stage bus ride or about a half-hour walk. The airport shuttle will drop you off at the hostel door for a fee. One major advantage is plenty of free, on-street parking as well as a parking lot in front of the hostel. (If you have a car, you will have a very difficult time finding parking in the city and it will cost a fortune.) The front desk is very helpful and will give you a map to help you find your way around as well as tell you how and where to catch the bus to the city or find your way up Mt Eden.
Rooms and Bathrooms
The dorm rooms are clean and spacious and the beds are comfortable. The rooms are quiet at night, so you will get a good night's sleep. Each dorm room has a key and the doors shut automatically. The bathrooms are great since they are individual toilet/showers instead of the typical shared dorm bathrooms. Everything is very clean.
This hostel is like a big house with a large kitchen and dining room table as well as a great patio with a picnic table and chairs for sunny days. There is a TV room and computers with coin-pay internet as well as wireless. Many of the guests seemed to be long-termers so the atmosphere was friendly and welcoming. There are lots of young travelers from diverse backgrounds, great for socializing although not a noisy party hostel. There are lockers for small items like laptops, cameras, and other valuables -- although most people choose not to use them -- and the friendly man at the front desk will assure you it is a very safe place and no one will steal from you.
Pentlands is highly recommended and a great introduction to New Zealand if Auckland is your first stop. It is a much better choice than staying in the city centre -- much quieter, cleaner, and friendlier than some of the bigger party hostels.