Manually Mount a USB Drive
A USB storage device plugged into the system usually mounts automatically, but if for some reasons it doesn't automount, it's possible to manually mount it with these steps.
Go to Applications (or Main Menu) > Accessories > Terminal.
Enter sudo mkdir /media/usb to create a mount point called usb.
Enter sudo fdisk -l to look for the USB drive already plugged in, let's say the drive you want to mount is /dev/sdb1.
Enter sudo mount -t vfat /dev/sdb1 /media/usb -o uid=1000,gid=100,utf8,dmask=027,fmask=137 to mount a USB drive formatted with FAT16 or FAT32 system. OR:
Enter sudo mount -t ntfs-3g /dev/sdb1 /media/usb to mount a USB drive formatted with NTFS system.
To unmount it, just enter sudo umount /media/usb in the Terminal.