There are very few books written about kendama, and next to none in English. Luckily for English-speaking kendama players, in 2010 The Void wrote and published "Spike: Mastering the kendama" which is a very nicely written and illustrated guide to kendama. This book is recommended for anyone wanting to know more about the kendama and kendama tricks. 'Spike' was followed by 'Knees' and then 'Click', both are highly recommened for progressing players.
There are very few kendama DVDs or books available. Some of the best resources are free and on the web. For example, You Tube is a great resource for kendama tricks.
Presently we are unable to get any kendama DVDs.