Recently as I was preparing to teach a professional development workshop for teachers. I planned to recommend they use author's teacher guides as a way to celebrate curiosity in the classroom with nonfiction books . And I realized I didn't know of a source listing teacher guides specifically for nonfiction books. 
Of course, if you are reading a book written for children or teens and you visit the author's website, there's an excellent chance you'll find a free teacher guide at their site. (Someti...