Their site says "Set the Access Point Name (APN) to mobiledata"
So set the APN to "mobiledata", leave username and password blank and try which authentication type works (unsecured/PAP or secured/CHAP).
If a homepage has to be provided, just set
http://www.google.com/m (that's the mobile version of Google).
And connection type should be HTTP, as they obviously don't require WAP-proxy-usage.