You try plotting something in R on a Linux machine in an SSH session you'll get this nasty error message:
Error in function (display = "", width, height, pointsize, gamma, bg,:
X11 I/O error while opening X11 connection to 'localhost:10.0'
Turns out there's a very easy way to see graphical output over your SSH terminal. First, if you're not already using PuTTY for SSH, download putty.exe from here. Next, download, install, and run Xming. While Xming is running in your system tray, log into the Linux server as you normally would using PuTTY. Then type this command at the terminal to log into the linux server of your choice (here, pepperjack), with the -X (uppercase) to enable X11 forwarding.
ssh -X pepperjack.mc.vanderbilt.edu
If all goes well you should now be able to use programs that utilize graphical output or interfaces, which are running on the remote Linux machine rather than your local windows computer.
Xming - PC X Server
Xming download link on SourceForge