Coax feedlines should be "grounded" at your single point ground, Which should be located on an exterior wall, Near where the coax will enter the room.
Usually, Some type of copper plate or bar acts as the single point ground, The best method to route that outdoors to your ground system is flat copper strap, At least two inches wide, Not wire.
A single ground rod is really not much of a ground.
I would start with at least three, Maybe adding more later. Space the ground rods at least 12 feet apart.
"Saline" type soil should provide a very good ground. Use only heavy copperclad rods.
For good info on lightning protection grounding see: http://members.cox.net/pc-usa/station/ground0.htm
Be sure to also read the links provided to Polyphaser, etc.