I think the absolute authority on the KID is Kotronias stuff.
Only 3 of 5 volumes have been released at this point and we're pushing 1500 pages already. It'll be over 2000 pages of in depth analysis by the time he's done.
I've read a good chunk of it from white's perspective and his analysis is unbelievably good. Sometimes he defends his "equality" evaluation with absolute insane analysis where he manages to get an endgame where white is up two knights but loses his last pawn and stuff like that...
It's great work but it's excessive if you're a club level player looking to learn from scratch. In that case maybe Bologan's chessbase DVD is a good start.
I am looking to learn the kings Indian defense for black. Could anyone recommend books to learn it?