Baguazhang - Theory and Applications

As far as a Martial Art goes, Bāguàzhăng (八卦掌) seems to me the least likely to be treated on a book format. The rich and varied traditions, styles and approaches make a pure programatic book - as the ones usually seen for Tàijíquán (太極拳) - look very partial. In particular for a beginner like me, it is difficult to identify what are the good entry points.
This book overcomes these difficulties. Even if the technical overview is related to Swimming Body Baguazhang, a specific tradition, the content is laid out in a way that the western beginner can follow. And as any book on martial arts, it has to be approached as a support for the practice. The main use I have for this book is as a reference. The chapters on The Essence of Baguazhang and Training Concepts are extremely useful to frame the instruction received in the regular practice. It is really a companion book for the Baguazhang beginner.

The Song of True Meaning of Tàijíquán (太極拳真義訣) by Lǐ​ Dàozi​ (李道子)

One of the difficulties one may encounter when looking at the texts presented as important for the practice is their cryptic language. It can be understood that some of the inner experiences can only be passed on in poetic form. It is also understood that early texts come from oral traditions tend to come in "songs" or texts that are easier to memorize.
For example, this text has the suggestive name of "The Song of True Meaning of Tai Chi Chuan". It certainly attracts attention also because it is reported by two important authors like Yang Jwing Ming (楊俊敏) and Jou Tsung Hwa (周宗樺). So, definetely something that the serious practicant should pay attention to.
In the other hand, beyond the evocations it brings, it is difficult to have an indication of how it should influence our practices. At least, if it is not commented by the practice with a recognized Master.

太極拳真義訣

無形無象，全身透空。
忘物自然，西山懸磬。
虎吼猿鳴，泉清水靜。
翻江鬧海，盡性立命。

李道子

"No shape, no shadow.
The entire body is transparent as air.
Forget your surroundings and be natural.
Like a stone chime suspended from the West Mountain.
Tigers roaring, monkeys screeching.
Clear fountain, peaceful water.
Turbulent river, stormy ocean.
Develop your whole body and mind to their full extent."

From the book The Tao of Tai Chi Chuan" (太極拳之道), by Jou Tsung Hwa (周宗樺) and "Yang Style Tai Chi Chuan" by Yang Jwing Ming (楊俊敏) based on the translations proposed in both books.

Tai Chi Secrets by Yang Jwing Ming (楊俊敏)

This collection of original Tàijíquán (太極拳) texts, translations and commentaries is probably the most complete to date. Master Yang Jwing Ming (楊俊敏) covers a lot of material on the three books: Tai Chi Secrets of the Yang Style (太極拳楊氏先哲秘要), Tai Chi Secrets of the Wu Style (太極拳吳氏先哲秘要) and Tai Chi Secrets of the Wu & Li Styles (太極拳武李氏先哲秘要). There is material for a life of study and the books complement quite well the other handbooks proposed by the prolific Master Yang Jwing Ming (楊俊敏).
Some of the material is also present on the Lost Tai Chi Classics from the Late Ch'ing Dinasty, by Douglas Wyle. But the approach is different, as the "Lost Tai Chi Classics" cover it from the scholar point of view, here the texts are presented from the practicioner point of view.