The Complete Training of Horse and Rider by Col. Alois Podhasky (this book covers virtually everything from start to finish, and is often recommended. Podhasky was the head of the Spanish Riding School of Vienna, his other books are great as well).
Reflections on Equestrian Art by Nuno Oliveira (Oliveira is probably the most highly respect "Classical" Dressage master of our time. The book is not a step by step hand book but contains his comments on many different topic. This is a book you will want to read again and again as you learn more. It's more about the subtleties than the mechanical basics. Invaluable!)
Dressage for the New Age by Dominique Barbie (this book very much promotes the philosophy of "Classical" Dressage. It is all about being relax and light and getting the horse to respond without the force often used by "Modern" Dressage. This book will probably seem useless if your horse does not already have dressage training. Think of it as a "goal" way to do things.)
Riding in the Moment by Michael Schaffer (I have just discovered this book and it is wonderful. Very much aimed at the Classical Style of dressage and also VERY good at explaining how to ride each movement of the horse in the Classical style. I might read Podhasky's book first so you know the basic bigger picture, but then ASAP, I'd read this book to help you to start out right. In fact, I think I might read this book first. I'm thrilled with it. It's whole aim is to clearify the very muddy "language of dressage" and make it understandable.)
The Classical Seat and Dressage in Lightness by Sylvia Loch (I have not completely read either of these but they are highly recommended by Classical trainers and instructors).
Dressage with Kyra by Kyra Kyrklund. (This is really a horse "training book" by if you can find her 6 DVD dressage series, it is very helpful.)
Okay, that's it. I have lots of other books that not very good. These I listed are all excellent if you want Classical Dressage.
As far as my trainers, unfortunately they are not in the Midwest. One is Leah Conathan and she is located in MA or FL depending on the time of year. The other trainer, the one who has my 8yo Andalusian right now, is Bruno Gonzalez (and Tina Veder). They are located in FL. They specialize in Classical Dressage and in Iberian horses and are wonderful. They also founded the "Baroque Equestrian Games and Institute". If you go to their website you can find all the patterns, etc for their training phases and more. www.baroquegames.net .