The traditional presumption in higher education that subject-matter knowledge is sufficient for effective teaching is breaking down. One cause of this change is the growing knowledge about how people learn, a consequence of which is a heightened focus on student-centered teaching practices. Another is the increasing diversity of students seeking college degrees, who differ by age, background, expectations, and learning styles. At the same time, emerging educational technologies provide a bewildering array of new possibilities for teaching, some of which reinforce rote learning while others engage students in refining their understanding and constructing knowledge. In the face of all of these challenges, faculty need to be able to draw on various teaching strategies rather than relying exclusively on lectures and traditional laboratory exercises. Based on his own career and those of other teaching faculty, Peter Kugel (1993) has described a series of stages through which educators typically progress in learning how to teach. Initially, educators focus on themselves and their role in the classroom, worrying about how they will survive and whether they will be accepted by their students. Gradually they progress to greater focus on coverage of the subject matter. Finally, those who become highly proficient focus on the students as independent learners and try to help them develop interests and skills for lifelong learning. Many faculty first begin traversing this path when launching their careers as assistant professors, although surely their panic could be reduced and their initial teaching results be improved if they had begun to progress along this continuum while still in graduate school. Graduate Teaching Fellows in K-12 Education (GK-12) fellowships provide one way in which graduate students can begin learning to teach in a well-scaffolded environment. All those receiving GK-12 fellowships spend 10 hours per week working as science-teaching partners in K-12 classrooms and at least another five hours preparing to do so. Although the details of execution differ from site to site, all of the programs offer structured opportunities for graduate students to work side by side with experienced teachers and to reflect on their teaching experiences. The GK-12 program is only one of many possible ways to help graduate students learn how to teach. The fellowships are expensive and time-consuming, and they cannot feasibly be offered to more than a small fraction of prospective faculty. But lessons learned through this program could be extended to other forms of graduate-student professional development aimed at nurturing teaching skills. (Contains 1 table and 10 resources.)