Silently store up knowledge and ponder. One can gradually arrive at the heart's desire......The practitioner must carefully study. This is the treatise.
Tai Chi for Everybody by Karel and Eva Koskuba, published by Readers Digest, is most highly recommended.
This book has the complete first section of Lao Jia Yi Lu as taught by the Three Treasures School so is an invaluable tool for students. It also has detailed instruction on many other aspects of Tai Chi including silk reeling.
Introductory books for beginners:
Movements Of Magic Bob Klein, Frog Ltd
There Are No Secrets Woolfe Lowenthal, North Atlantic
Gateway To The Miraculous Woolfe Lowenthal, North Atlantic
Tai Chi Chuan For Health And Self Defence T.T. Laing, Vintage Books
Intermediate and Advanced Reading:
The following books are important reading for those who develop a strong interest as these are translations of original works (Classics).
Cultivating The Chi Stuart Alve Olson, Dragon Door
The Intrinsic Energies Of Tai Chi Chuan Stuart Alve Olson, Dragon Door
The Essence Of Tai Chi Chuan The Literary Tradition (Taiji Classics) Lo/Inn/Amacker/Foe, North Atlantic
Tai Chi Touchstones Douglas Wile, Sweet Chi Press
The Tai Chi Boxing Chronicles Kuo/Guttman, North Atlantic Books
The Five Levels of Taijiquan Grandmaster Chen Xiaowang, Singing Dragon Books
Other recommended books include:
Mind Over Matter; Higher Martial Arts Shi Ming/Siao Weija, Frog Ltd.
Chen Style Taijiquan – The Source of Taiji Boxing Davidine Siaw-Voon Sim and david Gaffney, North Atlantic Books
Chen: Living Taijiquan in the Classical Style Master Jan Silberstorff
Chen Familly Taijiquan Form Manual Contact three treasures taiji for details
There are other interesting books on the market. Avoid those that are glossy and those that are mostly pictures of the form (they will invariably be different to the form you are studying, and it is very difficult to learn from them)