I had been using quite different set of tools to this but this is really good. Just install the gnome-disk-manager with
sudo yum install gnome-disk-manager
The interface is very clean and easy to understand and is it very very fast when compared to the other Graphical utilities.
Here are some screenshots to take you through.
Select the unallocated space to create a new partition, enter the size and type and press create to create a new partition. Cant get any simpler than this.
Supports even Ext4 filesystem.