In 1999, I wrote a book called Learn This! I published it only after several frustrating years of noticing how many things my daughters hadn't learned by the time they got to high school.
The book has twenty-two double-page spreads, each addressing basic information in a variety of subjects. It begins with the biggest topic, the Universe, then moves into the Solar System, the Earth, Continents & Oceans, Countries & Cities, and so on. There are two-page spreads on US presidents, US geography, Canadian geography, major religions, languages, and other topics. A few of the subjects, such as Math, Science, World History, and Writing & Grammar, take up four pages each.
Now I've taken those subject spreads and separated them into individual products. The book and its sections were intended as an overview. Yes, it's filled with facts, and facts alone do not comprise an education. But without basic information about the world, it's hard to move on to larger thinking.
I've tried to present the information in a friendly, and sometimes entertaining, way. Most spreads feature a section called "Don't make these mistakes anymore!" For example, in The Earth: "Astronauts in orbit experience weightlessness, not because there is no gravity, but because the speed of their spacecraft balances the force of that gravity" and "Mass and weight are not the same. The mass of an object is fixed and measurable -- how much substance the object has. Its weight depends on the strength of gravitational force." Essential terms are also explained.
Each spread is illustrated with photographs, drawings, maps, diagrams, or cartoons.