Hi chocaholic81, welcome to Talk3G.

The 3 GPRS settings are:
Homepage: http://mobile.three.co.uk/
Access Point (contract): three.co.uk
Username : guest
Password: guest
Authentication: Normal
You may also want their MMS settings:
Access Point Name: mms.three.co.uk
Username: blank
Password: blank
Gateway IP (proxy) address: 217.171.129.2
Port number: 8799
MMS Message (Relay) Server URL: http://mms.um.three.co.uk:10021/mmsc
Good luck with the above