Migrating Itunes music from old Macbook to new one

I used the Migration Assistant to migrate everything (including user account) from old to new Macbook. However, when firing up Itunes it did not find my music. I found the folder where the music should be, but when I try to access the folder it says I don't have permission (even though the account has admin privileges). So my questions are A: Why can't I access the folder? I copied the folder elsewhere on my harddrive and can access the copied version, but now I can't delete the old music folder (it says the folder is necessary for the OS). So B: How can I clean up that folder if I can't access the contents and can't delete it? And finally, is there a better way for me to move my Itunes library from one computer to another?