sudo apt-get install vnc4server
which will launch your session.
if your client computer is windows you can use:
If your client computer is linux, then take your pick for clients. I like Remmina
If your client computer is Apple, I think you can just use the native RemoteDesktop application.
Some other notes:
For Ubuntu 14.04, I installed gnome-panel, and then edited my ~/.vnc/xstartup to look like this:
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
gnome-session --session=ubuntu -geometry 1280x930 -ls -title "$VNCDESKTOP Desktop" &