Both links below are good lists of Bujinkan seminar that are occurring around the world.

Kesshi List

Kutaki no Mura

Articles

About Musaaki Hatsumi - here

Biography of Toshitsugu Takamatsu - here

The Autobiography of Takamatsu Toshitsugu - here

Training at home - here

Jupp Sessho no Jutsu - here

Mahoutsukai Dojo Articles - Lots of good articles in their archive section

"Ninjitsu - Misunderstood Art" - An excellent article by Ed Lomax

Ura & Omote - A massive collection of old articles and interviews

Interviews

Grandmaster Musaaki Hatsumi Interviews:

Ninja Grandmaster Says Goodbye to the West - here
1997 Tai Kai Interview with Soke Dr. Masaaki Hatsumi - here
Martial Arts and Effectiveness - here
Q & A with Masaaki Hatsumi - here

Videos

Mind Body and Kickass Moves - extract from a documentary on Hatsumi and the Bujinkan

What is Bujinkan Budo Taijutsu? - a good short demonstration

Bujinkan Budo Taijutsu - part of outdoor seminar

You can view many videos in the public domain on YouTube and Google Videos. Clicking these links will take you to see a search result on "Bujinkan" for each site. Searching on "Hatsumi" will also yield some good results.

Techniques

Rolling / Ukemi - a primer on ukemi by Masaaki Hatsumi

Tsuka-maki - The Art of Japanese Sword, lots of good images about how to do Tsuka-maki

Tsuka-maki Styles - shows lots of different styles of Tsuka-maki

Images

Toshitsugu Takamatsu - A comprehensive gallery of photos.

Dictionaries

Bujinkan Budo Taijutsu Japanese Dictionary - a comprehensive list of Japanese terms

Impact Ninjutsu Dictionary - a (non-Bujinkan) of dictionary Japanese ninjutsu terms

Forums and Podcasts

Kutaki no Mura - Worldwide Bujinkan Forum - Many good practioners and some Shihan regularly visit this site and post comments. A great place to share experiences or ask questions about all aspects of the training.

Kutaki no Ha - Bujinkan Podcast

Martial Talk - a general martial arts forum