If you want to learn the North American style of riding, I highly suggest you look at George Morris. He has written quite a few book on Equitation. I am sure he has DVD's out there - what I suggest is googling him and seeing what you get book wise.
I went to www.amazon.com
for you and this is the list I got:
You can look at what books you are interested in and see if Barns And Noble carries them or can order them in for you.