Is there any difference when I am installing floating floors over linoleum compared to concrete? Do I still need a moisture barrier/padding underlayment? I am transitioning from a carpeted room to one with linoleum and I was wondering if I needed to do anything different.
Thanks in advance.

If the vinyl is intact, you are good to go. You should tape any tears with cellophane of foil tape. You should use a pad, though. It will be pretty loud otherwise.