sorry but the question is not so clear.. maybe it's a problem of mne, but I can't understand what exactly is the point..
1. do you have yet mounted your USB or CD device?
2. did you do it with a file manager (thunar, nautilus, etc. etc.) or manually?
now: if you haven't still mounted it you must authenticate as root (or use sudo, indeed) and:
mount /dev/YOUR.DEVICE /media/zip
your device is usually sr0
(and so on) or sg0
(and so on) for CD/DVD drives.. it depends by the PATA / IDE / SATA specific of the drive itself..
if the device is an USB ones, usually you can find it in
if it's partitioned with more than one partition, of course); if you plug a second USB device you'll find it in sdc1 and so on..
is the mount point: if you are manually mounting the device you have to specify it; if you use a file manager usually the devices are automatically mounted in
I hope that I've been sufficiently clear to help you.. let me know..