In this new window, click the cdrom that says “Empty” under controller IDE to select it. Then click the small cdrom icon to the right of CD/DVD to associate it to your ISO file you download before.
You should have a window that looks like this. And finally click “OK”.
You should now have a virtual machine ready for the installation of Debian 8.1.
Tutorial 02 – Installing Debian 8.1 in a VM to come …