First you plug your USB hard drive in your USB port. Then open a terminal. Type su, to switch to root user. Once you are root, do a fdisk -l to see where the hard drive is. It should produce results in form of /dev/hda1 /dev/hda2 /dev/hda3 (these are the lines of your primary harddisk. The USB harddrive should be /dev/sda1 or seomthing starting with sd. If it's not, just analyse what the harddrives in your computer are.
Like for example. You know you only have one harddisk in your computer. That one is certainly /dev/hdax (where x are the numbers of partitions). IF you have two harddisks in your computer, then the second one is /dev/hdbx and the third one is /dev/hdc..... and so on.
Just eliminate the ones you know are not the USB harddrive. But as I said, the USB harddrive should be like /dev/sda1. Also in the line of that, you see the filesystem type of that drive. In your case it should say FAT something.
SO remember, just switch to root, and "fdisk -l" to see where it is.
Once you know where it is, and what filesystem type it is, you just have to mount it. To do that, you first need to create a directory.
mkdir /myusbdisk (this creates the directory)
and then just mount it there with the command:
mount -t vfat /dev/sda1 /myusbdisk
This is true, if you find it at /dev/sda1 and it is FAT filesystem.
Then just navigate to the directory /myusbdisk and there is your data. If you want to make it auto mount, just edit your /etc/fstab file. Just follow the examples already in it. Copy a line and change it to suit your needs.
I want to thank "marghorp" for the excellent way he/she laid the mounting process out. It now make sense. I have only one problem; My USB Harddrive is NTFS, and I get a error that say my 2.66 kernel donesn't support it:
I think it said this "fs doesn't support NTFS". I am at work so it is hard to remember all of it, I can reproduce it if it is required to fix the problem.