Your DNS settings are what directs people entering your domain name to the Webvanta servers. (Your DNS is typically provided by your domain registrar, though it may also be provided by a separate DNS provider.)
The preferred way to set up your DNS is to use a CNAME for www.domainname.com and domain forwarding for the base domain (domainname.com). These are the two steps:
The second item is not strictly a DNS feature, but it is offered by most DNS providers:
See Setting Up Your DNS with GoDaddy for blow-by-blow specifics on setting your DNS there.
If your DNS is hosted somewhere that cannot provide the forwarding service for the base domain, you can use this numeric IP address:
Then set the CNAME for www to ssl.webvanta.com.
Once you make the change, it will take anywhere from a few minutes to a few hours for everyone to see the new site, since DNS information is cached at many locations throughout the web infrastructure, and also by each computer and browser. Usually the changes show up within an hour or two.
If you are using DNS Made Easy, just set up an ANAME record for the base domain with the value of mysite.webvanta.com, and CNAME for www with the value of mysite.webvanta.com.
If you have a custom SSL certificate set up with Webvanta, then you must use www1.webvanta.com as the CNAME value, instead of your-subdomain.webvanta.com. This routes requests for your site to a different load balancer, which has the custom SSL certificates installed.