This is the first thing I do when logging into a dedicated or virtual dedicated server:
su - visudo User_Alias FULLTIMERS = youruser User_Alias PARTTIMERS = anotheruser Defaults:FULLTIMERS !lecture # full time sysadmins can run anything on any machine without a password FULLTIMERS ALL = NOPASSWD: ALL # part time sysadmins may run anything but need a password PARTTIMERS ALL = ALLTags: centos, intro, introduction, linux, man, sudo, tutorial, unix