Tap into Settings from the Main Menu
Tap into General
Tap into Cellular (some models say Mobile Data)
Ensure Cellular Data is ON (some models say Mobile Data)
Ensure Data Roaming is ON
Ensure Enable 3G is ON
Tap into Cellular Data Network (some models say Mobile Data Network)
In the Data section at the top, tap on the APN field and write internet
Also add the following settings if you wish to set up MMS:
In the MMS section, tap on the APN field and write mms
Tap on the MMSC field and write http://mms.2degreesmobile.net.nz:48090
Tap on the MMS Proxy field and write 118.148.001.118:8080
Tap on the MMS Max Message Size field and write 312200