There is a handy tool in Fedora 5 (not sure about the previous releases) that shows what devices are mounted in little boxes in the toolbar. You can add it right clicking one of your desktop panels and clicking add item. When in that window, you should be able to find an item called Disk Mounter. With this, you can just click on the desired volume and mount and unmount it as you see fit.
Hope this is handy,