" I do not know how to make my 3 installation CD's from the files I downloaded"
Log in as root and use the cdrecord command. Here is an example of using cdrecord for a CD-RW:
# Erase the CD-RW
cdrecord -force blank=fast dev=0,0,0 speed=24
# Copy the CD image file to the blank CD-RW
cdrecord -data -eject speed=24 dev=0,0,0 /root/data/psyche-i386-disc1.iso
If you are burning a CD-R then you can omit the first cdrecord command. See:
Be prepared. Create a LifeBoat CD.