Someone else recommended this book and I'm sorry I've forgotten who that is so I can't give them credit. World-building by Stephen Lee Gillett It's a planetary science for the lay person as it relates to science fiction world building. I know a lot about planetary science, as it's one of my hobby sciences. But there was a lot of useful information for me in the book. For example the planet in my world has a ring. It never dawned on me I should build in the effect of the shade the ring would cast on my planet's temperature and seasons. And there's a discussion about how certain elements might end up concentrated in the soil in different locations on a planet. The underclass in my novel just got some toxins added to the part of the city they've been relegated to. It's about the science, not fantasy, but highly recommended.