Hi
You can use the following link in order to follow the configurations
http://cisco.com/en/US/partner/products/hw/vpndevc/ps2284/products_configuration_guide_chapter09186a00801f1fb6.html
Also, Webvpn is user based, it is not associated with a group specifically as it is in IPSEC. But, if you want to lock one particular user to a specific group through Webvpn, you would have to use a Radius server with attribute "25" on it.
Otherwiase if you do not want it to be on a group basis, you can confiure it as general for all.
Make use the authentication method for WebVPN is on top of the list under configuations -> system -> Servers ->authentication
Hope this helps.
Please feel free to post your quesries
Thanks and Regards
Wakif