If you're using an IDE system and the USB stick doesn't mount automatically.
On the command line, as root:
mount -t vfat /dev/sda1 /mnt/usb
You can shortcut (symlink) to the /mnt/usb folder with
ln -s /mnt/usb ~/Desktop
(Do the above command as user not as root).
You might need to make the /mnt/usb folder writable for users.
If you're on a SATA machine then
mount -t vfat /dev/sdb1 /mnt/usb
If neither work then unplug the usb stick and then plug the usb stick back in and open a terminal and type, as root, tail -f /var/log/messages and watch the messages that appear in the terminal to see which /dev/xxx the system assigns to the usb device then append one of the above commands.