Are you wanting to backup your tagging info or your actual digital files or both?
For backing up your database...your authors, captions, categories, etc...I recommend using the backup function under tools|backup database and don't check the box by 'include file of type'.
Here's a tutorial to walk you through it.
For backing up your digital files there's a synchronize feature...you can run it to both the EHD and your backup HD and it will know what's changed or added so after the first one they won't take nearly as long to run.
Here's the tutorial to show you that one.
Now here's the fun part. When you run the backup database wizard, put the backup in a folder somewhere in your digi-stash. Now when you synch you'll get a backup of your backup. Can't beat that!
Using 'Move to' or 'Copy to' on a large number of files at once is not recommended...don't ask me how I know! (Yes, I wrote
speed tagging after having to start over
several times! LOL!)
HTH!
Kristi