PS - I did nothing special to "prep" or format my Western Digital 2TB hard drive. I use Time Machine for back up to that same ext. hard drive. Since I only keep the basic iTunes software on the computer and have no significant library associated with it, backup does not duplicate my iTunes library on the external hard drive.
You might be well served experimenting with "exporting" just a portion of your library - 1 or 2 saved CDs - until you get the hang of things.
You might be well served experimenting with "exporting" just a portion of your library - 1 or 2 saved CDs - until you get the hang of things.