Source Port: 3389, or use 8080 if you are behind a strict firewall policy.
Destination Port: (RDP Server IP or Hostname):3389
Make sure "Local" is selected.
Leave IP version settings alone (Auto).
Now Open the connection to the SSH Server, Login, open your RDP client and login to Localhost:3389 and replace the port with whatever you have put in the Source Port in PuTTY or KiTTY.
If the default RDP client installed in windows is blocked from being opened, Make an empty file and call it "Remote.rdp"
Just in-case you are doing this in a restricted network, or at School, please note that:
I will not be held responsible with what you do with this How-To, if you get yourself in trouble it is solely your fault.