VNC server - get your pi desktop on your mac

download vnc for the mac here 

first ssh from your mac to your pi. see how to do that here

then on the pi download and install VNC,open terminal and type

sudo apt-get install tightvncserver

start VNC on the pi, by typing in the terminal

sudo tightvncserver

(give it a password different to the pi- on first time install)

then on mac launch vnc viewer

vnc will want to connect to the pi- input the pi's ip address and then password .