Whet is the command for mounting the CD_ROM?

If you are putting in a audio cd you don't mount it.

If you are trying to look at data make a directory someplace to mount it to.

as root

or take a look in /media and see if it has a directory named cdrom0 if so then as root or sudo

to un mount

mount will require a filesystem type to be defined (does so on my system), so it will be something like
mount -t iso9660 /dev/sdc /mnt/directory-name
to follow-up on the previous sample.

Linux

To defined the file system,I think the command would be
mkfs -t iso9660 /dev/sdc /mnt/directory-name
inspite of
mount -t iso9660 /dev/sdc /mnt/directory-name

No, mkfs creates filesystems. All you want to do is tell mount which system the CD uses. Actually, you may not even need to specify the -t option when mounting, but doing so won't hurt.

Usually, you should have a symbolic link, /dev/cdrom that points to the actual device (like /dev/sdc), so you can use that. Also, you usually have an entry in /etc/fstab for the CD-ROM, which means a mount point for it will already exist and you can just do "mount /dev/cdrom" (or whatever the device name is), which may need to be done as root. Attach your /etc/fstab to your next post if you're unsure.