For the most part, you need to tell Linux what to do. This gives you a lot of freedom, because it does what you tell it, but people new to Linux have a number of pre-conceptions from Windows. One thing you need to do is to tell the system to mount devices like hard disks and CD-ROMs.
Typically Linux sees the CD-ROMs the same way it does hard disks, since they are usually all on the IDE controllers. The device /dev/hda is the master device on the first controller, /dev/hdb is the slave device on the first controller, /dev/hdc is the master on the second controller and /dev/hdd is the slave device on the second controller.
To mount a filesystem/disk you use the mount command. Assuming that your CD-ROM is the master device on the second controller you might mount it like this:
Sometimes /media/cdrom does not exist, so you might want to try this.
Sometimes the system already know about the CD-ROM device, so you can leave off either component:
You can then cd into /media/cdrom and you are on the CD.
Details on this can be found in the section on
hard disks and file systems.