How to assign the Roles for Portal devolpers

Hi,

How to give the roles and groupes to the Portal devolper as a Portal Adminstrator .

Which roles or groupes i need to give?

In one switchvation i have given System admin and content admin roles to that user by that time he is not able to Create the iview .At that time i have given Administrator and Every one group then only he can able to create the iview but here one porblem he got Useradmin tab also .

How can i manage with out getting the User admin tab?

please help me .

Regards

Srinivas