After checking my shelves, I said I didn't think so. You'd probably need at least three books just to cover the basics. One on history, one on modern-day politics (including gaming), and one on pop culture (Indians in entertainment, advertising, etc.).
I did point him to a couple of FAQs:
American Indians 101--Frequently Asked Questions
American Indian FAQ for Kids
I also could've pointed him to my Essential Facts About Indians Today.
Tellingly, the two FAQs answer different questions with little overlap. That shows how hard it is to tell everything you want to know about Indians in one posting.
So what's the problem?
Indians originally had thousands of cultures spread across two continents--fewer now, alas. But multiple cultures are true of any significant race or religion--e.g., Africans, Asians, Christians, Muslims. For any significant group, you'll have many of the same questions: how many are there, where do they live, what do they believe, what do you call them, what's the difference between subgroups, etc.
Of course, Indians have roughly twice the recorded history of other minorities in America. And they have an infinitely longer prehistory here. That means the history portion of any FAQ or book has to be longer.
But the real problem is that Indians have unique issues that don't apply to any other American minority. These include:
You could write a book about any of these subjects, and people have. When you consider the Indians' much longer history, plus the subjects unique to them, you can see the problem. I'd say Indians are several times more complex than any other racial or religious group. That's why it's so difficult to encapsulate them in one FAQ or book.
For more on the subject, see The Best Indian Books.