The general topics:
000s General Knowledge: Almanacs, Encyclopedias, Libraries, Museums, Newspapers...
100s Philosophy and Psychology: Death & Dying, Ethics, Feelings, Logic, Making Friends, Optical Illusions, Superstitions...
200s Religion and Mythology: Bible Stories, Buddhism, Christianity, Judaism, Islam, and other world religions; Greek, Roman, and other myths...
300s Social Sciences and Folklore: Careers, Customs, Environment, Families, Folktales, Government, Manners, Money, Recycling...
400s Languages and Grammar: World Languages, Sign Language, Dictionaries...
500s Math and Science: Animals, Biology, Chemistry, Dinosaurs, Fish, Geology, Insects, Physics, Planets, Plants..
600s Medicine and Technology: Cookbooks, Engineering, Farming, health, Human Body, Inventions, Nutrition...
700s Arts and Recreation: Architecture, Crafts, Drawing, Games, Jokes, Music, Sports...
800s Literature: Children's Literature, Plays, Poetry, Writing...
900s Geography and History: Biographies, Countries, Native Americans, States, Travel, Wars...