As is widely recognized in the teacher education field, it is a complex process for teacher candidates to become effective classroom teachers. With growing linguistic and cultural diversity in today's classrooms, as well as different social expectations for education, the teacher preparation process is becoming increasingly demanding and challenging. Further, the characteristics of the preservice teaching force are changing as teacher candidates of the millennial generation enter teacher education programs. In particular, teacher educators who prepare secondary preservice teachers need to provide support in areas beyond content expertise and pedagogical knowledge. While many researchers report the reality shock teacher candidates experience during the process of "becoming" and discuss the struggles and confusions that teacher candidates confront during their professional identity development, continued research is needed for teacher educators to learn from teacher candidates' experiences and their journey of becoming. Such feedback will lead to the development of more effective teacher education programs that prepare highly qualified teachers for 21st century school-age populations. In addition to examining the impact of selected components of their teacher education program on teacher development (He & Cooper, 2009), the authors were particularly interested in learning more about teachers' concerns and struggles on their journey of becoming. Through autobiographies, interviews and focus groups, the authors followed the development of seven secondary teacher candidates over the last two years of their teacher education program. In this study, the authors intended to focus on: (1) the development of teachers' self-perception of their roles; (2) the major concerns of their teacher candidates; and (3) the reasons behind these concerns. Two major research questions were addressed in this study: (1) How do secondary teacher candidates perceive their roles as teachers before and after student teaching?; and (2) What are secondary teacher candidates' main concerns and sources of such concerns before and after student teaching? The authors' interpretation of the implications for teacher education programs is provided. Additionally, through the exploration of their candidates' journey of becoming teachers, the authors as teacher educators can potentially gain insight into their own professional journeys with the goal of improving not only their candidates' professional preparation but also their own professional practice. (Contains 4 tables and 1 note.)