few things. with ssh you will need to add the -X tag and also have X11 forwarding active on the remote system, but you can get a full desktop IIRC via ssh -X user@IP.
vnc, google for it it is a very powerful tool. not very secure, but for LAN use it should be more then adaquate to help you get a remote desktop. it can if configured properly even give you the active desktop :0 so you can controll what is going on, but most people i know just have it set to :1 or some other desktop so you do not interfer with anything that might be going on on that workstation/server.