1) Ensure your DNS has fully propagated
2) Try surfing other sites ie google.com
3) Ask a friend/associate to point to your site from a diffrent PC... different ISP if possible OR use a proxy site
4) Ping your site by domain name and IP
5) Do a tracert by domain name and IP
6) Check for Forum Announcements for your server(s) to ensure the outage is not scheduled maintanence
7) Check your email
8) Perform a tracert to your site, Then go to the "Customer Area" Send us a support ticket including the tracert results.