Effective meaningful relationships in schools that are grounded in the common purpose of student achievement and progress result in effective teaching and learning. Such relationships require personalized environments. Schools large and small must purposefully create conditions that enable students and teachers to come to know and be known well by one another. When such is the case, each student's capacity to learn to use her or his mind well--to think clearly and act wisely--is greatly enhanced. This article--born of both success and failure experienced during three decades of working with students, parents, and colleagues--describes one way to personalize the educational experience for students and teachers alike in high schools: advisories. Advisories address an important, basic need that is required for each student to be successful: conditions that lead to the creation of effective relationships. The purpose of what the author calls "advisories" is to increase student achievement and progress, decrease student isolation and alienation, and personalize learning and the school experience. This article also explores five key dimensions for creating and sustaining advisories in high schools: (1) Purpose; (2) Organization; (3) Content; (4) Assessment; and (5) Leadership.