Creating an ISO, a CD/DVD image, in Ubuntu Linux is not hard at all, The first thing that needs to be done is Opening the terminal (Applications -> Accessories -> Terminal)

In the terminal type in the following code:
CODE

sudo umount /dev/cdrom
dd if=/dev/cdrom of=file.iso bs=1024



If you would like to mount the ISO, so that you can access the files within the ISO file you must type in the following code into the terminal:
CODE

sudo mkdir /media/iso
sudo modprobe loop
sudo mount file.iso /media/iso/ -t iso9660 -o loop
Note: "file.iso" is not the exact thing that you type in, it is whatever the iso's name is

Remember that when you are finished you should unmount the ISO file by typing the following code into the terminal
CODE

sudo umount /media/iso/



Last but not least, most likely you would like to burn the ISO onto a CD/DVD which is the easiest part, since it does not require the terminal. First Insert a blank CD/DVD into your CD/DVD burner next locate where the ISO file is located then:
Right click on Image (ISO) file -> Write to Disc... -> Write

Please feel free to correct me if i am wrong.