Here are some useful links for yourself and your clients to use once their accounts are created in WHM.
“Before propagation” as it is defined below is the point between when you sign up and when the changes to your name servers take effect (usually about 48 hours after you change your name servers).
“After propagation” is once your site is up and running normally.
During propagation, you should use the “Before propagation” format.
Service Before Propagation After Propagation
cPanel http://12.23.345.67/cpanel http://example.com/cpanel
WHM http://12.23.345.67/whm http://example.com/whm
Webmail http://12.23.345.67/webmail http://example.com/webmail
WebSite http://12.23.345.67/~username http://example.com
Replace “12.23.345.67” with the IP address of your server, and replace “example.com” with your or your customer’s domain name. The “username” would be the username you specified in WHM when you created the account.