I noticed people are confused about how Time Machine backups work with My Book Live. If you have a Mac, migrating your existing Time Machine backups onto your My Book Live device is critical. In this blog, I show how you how that is done.
In particular you should read this blog if you try to copy your Time Machine backup to the drive manually, and you get this error: The volume is the wrong format for a backup.
http://rschilling.wordpress.com/2013/03/03/migrating-mac-osx-time-machine-backups-to-my-book-live/
I hope this is helpful.
Cheers!