Folks a few basic questions.

With and adjustable feed-horn on a C120 flange LNB what should the start point for the feed-horn distance to end of feed tube be, i.e should it be flush with the tube or back from its end? How do I set up or tune the feed-horn? by using the signal strength setting peaked to max or use the s/n reading on the meter? In other words what effect will I see when the horn is out of alignment?

Also when setting up a polar mount should the center line of the mount start off pointing TRUE SOUTH?
Is there any detailed tutorial, DVD book or web site that shows the setting up of a motorized setup using a V-Box polar mount?