I get this question from time to time and there are a number of causes.
"I try to login to cPanel but after I enter my login information, it just keeps loading (clocking) and never lets me in."
Possible cause: Firewall at your current location.
Some corporate firewalls block the port that cPanel uses to connect.
Instead of going to http://www.yoursite.com/cpanel, please try htpp://cpanel.yoursite.com instead. If that path works, then you likely have a firewall issue.
Possible cause: Server issue.
If both paths just clock, please open a ticket as there may be a server-wide issue we need to correct.
Thanks!