Based on another recent thread about a certain politician, I'm motivated to start one on recent(ish) valuable popular-audience science books that are available as ebooks. Given that the discoveries of evolution and deep time are fundamental cornerstones of modern biological and geological sciences, learning about the history of life on Earth and how that history is unraveled is amongst the most important areas of human knowledge-- and some of the least understood by the lay public. So here are a few useful books for anyone with a thirst for learning. (There are plenty of other titles I have skipped because I didn't find an "official" ebook version of them.)
A great start would be the recent books Your Inner Fish
Only A Theory
and Why Evolution Is True
And I'll go out on a limb and mention Dawkin's most recent book, even though I haven't read it yet:
Then for the discovery of deep time itself, there is the great book The Map That Changed The World
along with a book on James Hutton (I haven't read this particular book-- the one I wanted to recommend doesn't have an ebook version)
Other good science book recommendations (no matter what the field) encouraged.