Webmin on CentOS 7

Here's a great resource page for installing Webmin:

http://www.webmin.com/rpm.html

If you can't access the Webmin login screen when you are done, (https://[server-ip]:10000) then you may need to review your firewall rules. 

For IPtables, this worked for me: http://www.webmin.com/firewall.html