I am assuming that you are using red hat linux enterprise edition ? If so the USB pen drive should be automatically recognized and a mount point set to /media/<drive make> . Should also place an icon on your desktop. You have to "mount" the drive to access the data on it and this can by achieved by right clicking on the usb icon and selecting "Mount Volume." Alternatively fire up a terminal and issue the command mount /media/<drive make> or even navigate using nautilus to /media/<drive make> and mount from there.
You have to be root or use "sudo" when issuing the mount command.
Use the umount command to unmount the drive.
ps : All the relevant RH Enterprise manuals are here :