For the meta tag, just place that in the 'head' section of any page you want to exclude from the search engine.
I'm not familiar with Covad but generally web hosts have a "control panel" of some sort and in the file manager you can set individual permissions. There are three levels of permission; read, write and execute. What you want to do is set perms to owner or group only.
You can set them with your FTP, SCP program as well. Hope that helps.