This brochure provides an overview of the Coalition of Essential Schools (CES). CES is a growing network of over 1,200 schools and 20 regional support centers that promotes higher student achievement. The CES arose out of "The Study of American High Schools," led by Theodore R. Sizer, and began with 12 schools in 1984. Today, CES membership includes elementary, middle, and high schools in 39 states. The pamphlet describes the CES network and how CES centers and CES schools are connected to the national headquarters. It lists the ten common principles of CES: learning to use one's mind well; less is more, depth over coverage; goals apply to all students; personalization; student-as-worker, teacher-as-coach; demonstration of mastery; a tone of decency and trust; commitment to entire school; resources dedicated to teaching and learning; and democracy and equity. The text describes diversity in CES and discusses how CES are designed to ensure that students are recognized by their teachers and are fully supported in their academic, social, and emotional development. It details the importance of effective teaching and the need to have caring, competent, and qualified teachers. The document also offers summaries of CES programs in Massachusetts, Michigan, California, and Maine. (RJM)