Sean,

I am not sure whether you need this at the Admin or Host level, but either choice works the same way.

Select Admin (or Host) tab > Languages.

Choose Language Editor from the module action menu. (Click 'yes' to override if necessary)

Maximize Global Resources and click Global Resources (with the page icon).

It sounds like you want to leave verification on, so you'll need to edit the EMAIL_USER_REGISTRATION_PUBLIC_BODY.Text section located halfway down the page.  This is what gets automatically sent out to newly registered members who must enter in the verification code on the first Log In.