Hi
you can create test users in Account Operator / Server Operator - depending on what perms you want to give them.
Please check here for detailed options.
http://ss64.com/nt/syntax-security_groups.htmlHow to create restricted groups though GP
http://www.windowsecurity.com/articles/Increasing-Security-Limited-User-Accounts-Restricted-Groups.htmlDetailed explanation.
http://support.microsoft.com/kb/243330