When I lived abroad, I had a short list of books to help people understand the US more. It is a big, complicated country and it can be hard to find well-written works. Here are my top books to understand the US -
1) "American Nations" by @ColinWoodard - Woodard makes the argument that the US is not one nation but actually eleven different national grouping all vying for control. Gives you insights into odd quirks of American identity.