Open System Settings -> Appearance > Behavior tab and enable the Auto Hide. This will hide the panel and reveal itself when the mouse hits that side of the screen. The sensitivity of how hard the mouse has to hit for it to reveal is on the same screen and you can adjust that.
If you never want it to show, enabling auto hide, and turning the sensitivity all the way to low will give you the best results. However it will still reveal if you hit the side hard enough.
You can install a package called Unity Tweak Tool from the software center, or by running
sudo apt-get install unity-tweak-tool and the Launcher settings in that application provide a way to change the reveal location from the entire side, to the just the top corner.
That's about all you can do to stay away from it as much as possible, and doing the above will do a pretty good job. However, that launcher is a pretty important part of the Unity desktop environment, and if you don't like it, perhaps another desktop environment will suit your workflow more; something like Gnome, XFCE, or KDE.