Once you have an ssh session going to log into the Pi at the command line level and an Internet connection, you can install a VNC (Virtual Network Computing) server on the Pi. This will allow you to remotely log into a Pi graphical user interface (GUI) desktop over a wired or wireless network from any Linux, WIndows, Mac, smartphone, tablet, etc., device after installing a VNC client on the display system(s). One of the more popular VNC implementations is TightVNC
due to its speed and minimal resource load on small computers such as the Pi.
A Google search will reveal a plethora of other VNC servers and clients, e.g., http://en.wikipedia.org/wiki/Virtual_Network_Computing
Note that you can have multiple VNC connections active from more than one remote system to a single Pi, although that will consume valuable memory and slow the Pi down even more than one VNC connection will (the visual response will always be at least a bit slower than having a display connected directly to the HDMI or composite port).
The best things in life aren't things ... but, a Pi comes pretty darned close!
"Education is not the filling of a pail, but the lighting of a fire." -- W.B. Yeats
In theory, theory & practice are the same - in practice, they aren't!!!