Research shows that the most powerful, in-school influence on learning is the quality of instruction that teachers bring to their students. In the next decade, more than 1.5 million new teachers will be hired for our schools; unfortunately, teacher preparation programs may not be up to the task of delivering the teacher workforce we need, and critics have identified lax selection of teacher candidates, coursework disconnected from classroom practice, and weak clinical opportunities as indications that we are inadequately preparing teachers. It's time to take a start-to-finish look at teacher preparation. For all of those involved in the work of helping students learn, teacher preparation is a central issue that must be addressed. Teacher preparation--from college courses to student teaching to alternative programs--needs to help beginning teachers learn to teach. Anything less will fail these new professionals.