When I’m working on a picture book, I usually raid my local library for any and all books that I can find on the topic. It’s fun to see what other authors have written about that topic—and how many different ways authors can explore the same themes.

My picture book Can a Rock Grow? explores different shapes that rocks can form, while introducing children to the rock cycle. For the past year or two, while I was working on this book, we’ve been reading read about rock collecting, geology, and th...