I'm not disagreeing with the books others have listed, and I have most of them. But I have a different one to suggest.
I have given copies of McIntosh's
Shotguns and Shooting to a few friends and relations who have gotten interested in shotgun hunting. Michael McIntosh is able to write about the grace of the beauties that are out there in a way that speaks to Americans. ABE Books has a used hardcover copy for $6.14 with free shipping this morning, and I don't think it will disappoint you.
Here's a link to the book on Amazon so you can see other reviews - personally, I'd buy the used copy on ABE: