After a quick introduction, the book plunges right into the information. The ten chapters each begin with a comic, featuring the Dirtmeister at a geology job, where he gets interrupted with a question about the earth from a kid. There are about five spreads per chapter, and each spread includes about one page of text, a handful of photographs and several other pieces of information ranging from experiments to "Dirtmeister Nuggets" which are factoids to short biographies of famous scientists and cartoons or maps.
Back matter includes a list of notes that relates the chapters to science curriculum, an index, and photo credits. I felt the cartoon illustrations were a bit over the top and tried too hard to be "kid-friendly" but they aren't so prolific that they take away from the information in the book and younger kids will probably enjoy them.
I felt a bit overwhelmed by the amount of information on such a wide variety of subjects crammed into this small book. Everything from plate tectonics to fossils, from earthquakes to diamonds. The experiments looked interesting, but tended to be a lot more simple than what I expected from the build up in the introduction. I certainly wouldn't recommend reading it straight through and I'm not even sure I'd recommend it to a kid who's interested in, say, rocks, since it's so wide-ranging and kids who are "interested" in something tend to have a rather narrow focus. However, it makes a great resource for earth science curriculum and I can see kids who enjoy compendiums of facts dipping in and enjoying it.
Verdict: This isn't my top pick for National Geographic's earth science offerings - kids are more likely to pick up the Everything series - but if you can't afford that entire series, this gives a little on a variety of subjects and would be a great resource for school and for kids to browse.