Educational/Informational horse books
Which horse books do you own because they are very useful when owning a horse. I'm really interested in learning more about the physiology, psychology, and nutritional aspects of horses. I've been looking online at books, but you can never really tell which ones are going to be useful in the long run and which ones just look educational. I did think about looking for an online class to audit for just this purpose, but I have more time for books than classes.
The wind of heaven is that which blows between a horse's ears. ~Arabian Proverb