Shiloh - in Hell before Night by James Lee McDonough
McDonough's book covers the battle of Shiloh from the brigade level on up. You will rarely read of the exploits of a regiment or battery. And that is fine, in fact sometimes it is good to get away from the minute details and think about the battle differently.
This is one of the classic books on the battle, along with Sword's, Daniel's and Cunningham's. One thing I like about the book is the maps. The maps are very clean and clear. They do only show things at a division level which is a drawback. They are also full page maps. I find it annoying when a publisher gives you a map that is only a third or half the size of the page. They often have too much information for that size. But when McDonough gives you a map or illustration it is as big as the page.
I don't have too much to say about the book except that it is a wonderful book that deals with the battle without going into regimental detail. If you wanted to find out what happened at Shiloh this would be the book I'd send you to. If you wanted to find out what the 15th Illinois did I'd recommend something else, probably Sword or Cunningham. But if you wanted the book to either build on what you just saw at the battlefield or to prepare for a battlefield visit this would be a good one to choose.