Moving iTunes (not that simple?)

Sometime ago I moved all my Music over to an external HDD, it all worked fine except everything got duplicated TWICE, and I'm still sorting through getting rid of multiple entries....anyway after a horrendous external HDD failure my trust in external HDD's has been dented somewhat, so I've decided to move my iTunes back onto the internal HDD on my iMac and use the external HDD for back up only of itunes.

On my External HDD I have the following Folders iTunes 1 Which contains the following folders: Album Artwork, Previous iTunes Libraries, and the following files: iTunes Library, iTunes Library Extras.itdb, iTunes Library Genius.itdb and iTunes Library.xml

I also have a Folder called iTunes, Copyright Free (I made this one) and Desktop

I don't know why I have iTunes 1 and iTunes Folders, I'm worried that I might remove/delete the wrong thing and lose all my Music/Videos/Films and Apps

Please help :-(

Thanks