While going over FM Steve Stoyko's games with the King's Indian Attack, I was inspired to do a little research on the line myself and may return it to my repertoire. I actually played it on occasion as a teenager before recognizing that it was too difficult for me. Steve himself said that it is not an opening he would recommend to developing players. As I try to add a bit of positional complexity to my e4-based repertoire, though, it now looks like a good choice.
The following bibliography is necessarily an incomplete list of references. The fact that the KIA can arise via 1.e4, 1.Nf3, 1.g3, or even 1.d3 makes classification difficult and there are likely a number of sources (including repertoire books on the French or Sicilian) where it at least gets a mention. From personal experience, I can recommend Angus Dunnington's The Ultimate King's Indian Attack and John Hall and Jan R. Cartier's Modern King’s Indian Attack: A Complete System for White. Both would make excellent additions to anyone's library. Many of the rest (excluding web sources) I only know from my research and therefore can say little about besides the basic facts.
Angus Dunnington, The Ultimate King’s Indian Attack (London: Batsford 1993 / 1998 / 2001)
I think this is the best opening book I have seen from Dunnington, who is rather prolific. He does the best job I have seen of trying to sort through the lines to systematize the KIA for opening theory. He also offers some excellent commentary on the games he gives, which tend to be a bit more contemporary than those offered by Hall and Cartier and much updated over earlier versions of this book (which have appeared under various titles).
Mark Dvoretsky and Artur Yusupov, Opening Preparation (Batsford 1994 / 2003)
Features a deep discussion of positional themes in the KIA.
Roman Dzindzichashvili, Roman's Lab 28 - Easy Way to Learn The King's Indian Attack
Gives an overview of the system by examining five games in some detail.
Heiko Eggers, Königsindischer Angriff (Eigenverlag 2005)
John Emms, Attacking with 1.e4 (Everyman 2001)
Emms offers the KIA as his repertoire choice against the French Defense, mentioning that it is not quite as effective against other lines – especially not against the Caro-Kann. Good coverage for a repertoire book. The rest of the selections--on the Bishop's Opening, Closed Sicilian, and others--fit together well.
John Emms, Starting Out: The King’s Indian Attack (Everyman 2005)
Exeter Chess Club, Introduction to The King's Indian Attack
A good introduction for club players to the basic patterns of this line.
Ron Henley, The King's Indian Attack (R&D Publishers 1993)
King's Indian Attack Games at Chessgames.com -- A07 and A08
Don Maddox, King’s Indian Attack CD (Chessbase 2002)
This CD has received rather mixed reviews and so I have not picked it up. It is always useful, though, to have a collection of games in electronic format to look at on the computer.
Malcolm Pein, How to Play the King's Indian Attack (Chrysalis 1999)
Pitt Archives, King's Indian Attack PGN file
A PGN file to download from the Pitt Archive.
Ken Smith, King's Indian Attack (Chess Digest 1976)
Steve Stoyko, Steve Stoyko Lecture (2005)
Discusses the game Stoyko-Formanek, U.S. Amateur Teams 1997.
Steve Stoyko, King's Indian Attack (2005)
An analysis of the author's games.
Eric Tangborn, An Opening Repertoire for White: The King's Indian Attack
A discussion of 10 games by Petrosian, all well annotated and worth looking at, with the promise of more.
Eric Tangborn, A Fischer Favorite: The King´s Indian Attack (Chess Enterprises 1992)
John Watson, Play the French 3rd Edition (Everyman 2003)
After offering several good lines for Black, Watson endorses the Karpov system with Nc6, Bd6, Nge7, and Qc7 in his 16-page chapter on the line.
Norman Weinstein, The King's Indian Attack (Chess Digest 1976)
A small pamphlet of under 50 pages in descriptive notation.