It's nice, but I don't have X installed. CLI only.
First you have to create a partition with fdsk /dev/sdX (where X is the letter of your each drive).
Then if you have LVM follow the LVM howto (http://tldp.org/HOWTO/LVM-HOWTO/).
If not you have to make a new filesystem and mount in a new mount point.
Or you can simply use Gparted from a live Linux distro.