If you want to mount a USB device on linux. (And are really tired of the shitty advice online)

First find the damned thing:

dmesg | grep -i SCSI

this will find all the scsi devices. Then you guess as to which one might be correct. A good guess might lead you to a line like the following

Attached scsi removable disk sdb at scsi3, channel 0, id 0, lun 0

where now you know that the removable disk is /dev/sdb

Now, that is not the end of the story, you still have to determine which partition on /dev/sdb is mountable. This I found to be necessary for mounting those USB keys which are formatted for Windows. if you perform;

fdisk -l

it will dump all information for all storage devices attached to your system (assuming they are powered etc...) 
For the case of the USB key returned the information that /dev/sdb1 was a boot partition, and consequently the mountable section of the device.

Now I bitch about some shitty instructions I dug up elsewhere...

you could go around the sun to meet the moon by trying such jewels as lsusb which tells you everything about the device except what you want to know. Or if that does not suit you try 

cat /proc/bus/usb/devices

which simply lets you know the status of all usb ports, however it still fails to tell you where the mount point needs to point to.

End of rant...

Once you find the device just make a mount point in /mnt/ and run

mount /dev/sdb /mnt/USB

(this is an example and will not necessarily work on your machine unless your device is on sdb and you created a mount point /mnt/USB)

with the information from fdisk -l you also know the format of the storage device. (For windows it is likely fat32, but do not just take my word for it, there is also an ntfs filesystem to watch out for.)