Go to where you purchased the domain and update the name servers to point to the ones in your welcome email. Then open a ticket with the help desk and ask them to park the domain over your existing account. That's all there is too it.
Welcome to the forums Tracey
Safest way to not get harvested is to use throw away email address when you sign up for things. And never use a mailto: link on your website.
Welcome to the forums Cygni
As TCH-Rick states, they should be listed and if not please open a help desk ticket with the support department.
The mods do not have access to the servers or your account information.
Ok when I was using Blogger I found it easier to create an FTP user just for Blogger.
Go into cPanel and create an FTP user called weblog and make sure it points to the "weblog" folder.
Over at Blogger:
FTP Server: ftp.your-TCH-domain.ext
FTP Path: /
FTP User: weblog@your-TCH-domain.ext
FTP Password: password you assign to FTP user
Blog URL: http://your-TCH-domain.ext/weblog
Blog Filename: index.html
That should do it.
While I don't know if it is possible on a dedicated server to do something like this it is doubtful on a shared server since they all use the same smtp server to send mail.