Create image in QEMU:
$ qemu-img create -f qcow2 $NAME.img 8G
Install or run with ISO image attached:
$ qemu-system-i386 -hda $NAME.img -cdrom $DISTRO.iso -boot d -net nic -usb
Best way to add mouse support via -usbdevice tablet because tablet device does not need to constantly grab mouse position:
$ qemu-system-i386 -hda $NAME.img -boot d -net nic -usb -usbdevice tablet