In Season 3 episode 2 , Dark wings, Dark Words the Character Orell has his eyes rolled back and an Eagle is circling above and Mance says to Jon Snow that he is a "warg". This is the first time we are shown a Warg. OK, by now we all know what a Warg is and in previous episodes Bran also is Warging, although he does not know it yet and we are not show what he is doing.
When Bran is Warging he seems to go pretty far away from his actual body while he is in the wolves consciousness. Orwell seems to Warg into an Eagle and when asked by Mance where he was (had been) and he states that he was at the
The Fist of the First Men and saw dead
I don't know how far away from the position that they were standing at was from the
The Fist of the First Menbut, is there anything in the books or the show that sates reasonably how far they can Warg?
I also understand that not all Wargs are created equal, as Bran seems to be an extremly powerful Warg as he is able to take over a humans consciousnesses.