Howdy all,
I just wanted to mention a really nice series of five articles at The Register that Trevor Pott did about Webmin, Virtualmin, Cloudmin, and Usermin:
http://www.theregister.co.uk/2010/09/14/sysadmin_linux_webmin/
http://www.theregister.co.uk/2010/09/16/sysadmin_linux_webmin_modules/
http://www.theregister.co.uk/2010/09/17/sysadmin_webmin_usermin/
http://www.theregister.co.uk/2010/09/20/sysadmin_webmin_virtualmin/
http://www.theregister.co.uk/2010/09/22/sysadmin_webmin_cloudmin/
Thanks, Trevor!