Help with ZyXel NBG4115 Setup

I want to setup a vodacom 3G dongle to the above mentioned Zyxel modem.
I have the pin number, I need to fill in the following details.
The APN number
The Dail Number
The User Name and the Password

I don't know what I have already or what I should put in. If anybody could help out it would be much appreciated.