Sensei Ed Martin and the Pennsylvania Dojo Website. Full of information, books, videos and training aids. An excellent resource for information on everything Bujinkan.
http://www.pabujinkanbarndojo.com/Ed_Martin/Bio.asp

For information on training in Japan, messages from Sensei, maps and links
George Ohashi - Japan Hombu Information

THE definitive Bujinkan site from the Source Himself
Bujinkan Dojo - Soke Masaaki Hatsumi

Fantastic information on the "dual-life values" of Robert L Humphreys, Bujinkan, Kids - in fact everything you need to know and probably a bit more!
Warrior Information Network - Jack Hoban

Gillian Booth and Frances Haynes's Dojo in Sydney
Courageous Heart Dojo

Duncan Mitchell's dojo in Queensland
Bujinkan Dojo Brisbane - Duncan Mitchell

Peter White's complete "who's who" of teachers and dojos in Australia
The Australian Komichi Dojo List

Great site - stacks of stories and histories on Takamatsu and Hatsumi Sensei and detailed histories of the 9 Ryuha
Missouri Bujinkan Dojo

The original and the best - Mats Hjelm's sprawling website on absolutely everything Bujinkan!
Kabuto's Bujinkan Website - Mats Hjelm

Discussion board for Bujinkan practitioners worldwide. Owned by Shawn Gray. Well moderated and lively discussions. Enjoy!
www.kutaki.org