Philosophy
What is the Purpose of Kendo? - This is an interesting question as modern Kendo is both a "sport" as well as a "Budo". While the sport aspect is rather simple to understand (exercise, comaraderie, tournament competition, etc..) the "Do" in Kendo is much more complex, as well as a very personal and individualized topic. The All Japan Kendo Federation officially set down the "concept and purpose" of Kendo in 1975. This definition emobodies the modern concept of a "Do".
When do I??! Why do I?!? How Do I?!?! - questions often left burning in many a Kendoka's thoughts when it comes to being able to deal with an opponent. This is a small excerpt from the Kingston Kendo Club's Dojo Manual regarding the "San Satsu Ho", "Mitsu no Sen" and "The Four Sicknesses". These topics give some insight into the (principles oriented) answers of when, why, and how you can attack (or be attacked by!) an opponent.
Mistakes
in Practice - a small excerpt from “Zen Mind, Beginner's Mind” by Shunryu
Suzuki. The connection between 'Zen thought' and Kendo is very apparent, as are the similarities in their practice methods.
While the subject of this book/article is that of practicing 'Zazen', the advice it gives is equally applicable to a
Kendoka in their practice.
Mindset for Keiko? Here is a small article written a few years ago regarding the mindset needed while performing keiko. I think that it is particularly useful to those who are relatively new to (Bogu) Kendo.