Try also, An Ocean Of Air by Gabrielle Walker. Although only supposedly about the atmosphere, she delves into a lot of subjects, especially interesting odd corners, and again it is a great lesson in how to tell the story.

Why not try Bill Bryson, A Short History Of Nearly Everything. It does not go into anything in great depth, and it makes a few school boy errors, but it is a great lesson in how to do the big overview, and organize it in an interesting and understandable way with a good narrative, especially for a none specialist addressing a none specialist audience.