In the following three studies we explore ways to improve the quality of school-based personnel by identifying characteristics and training of effective teachers and principals. First, to enhance the selection and hiring of teachers into preparation programs and/or school districts, we examine whether teachers' non-cognitive characteristics predict teacher value-added and evaluation ratings. This work builds upon research in psychology and economics which shows the impact of individuals' non-cognitive attributes on outcomes of interest. Here, evidence indicates that teachers' non-cognitive characteristics significantly influence student achievement gains and predict higher evaluation ratings. Due to the select sample of teachers examined in this analysis--Teach For America corps members--this work represents a "proof of concept" and calls for continued research on a more representative sample of teachers. Second, to better inform the choices made by states and districts in staffing schools, we question whether effectiveness differences exist between teachers traditionally prepared in-state versus out-of-state, and if so, we test three research-based hypotheses to explain differences. Overall, the findings indicate that out-of-state prepared teachers are significantly less effective than in-state prepared and alternative entry teachers in North Carolina elementary schools. Further, out-of-state prepared teachers' lack of familiarity with the state's educational environment and attrition patterns--high rates of turnover coupled with the attrition of less effective teachers--help explain their performance. This suggests policy mechanisms to increase the in-state prepared teaching population and improve the quality of out-of-state prepared teachers. Finally, to contribute to the nascent principal quality research agenda, we detail the characteristics of first-time principals and the schools that hire them. Further, we question whether individual principal characteristics or those of the environments in which they previously worked are associated with student achievement gains. Descriptively, we find that a majority of first-time principals are "homegrown"--promoted from within the district--and evidence that first-time principals sort into schools based on observed characteristics. Our strongest value-added results indicate that early-career principals who served in high value-added schools as assistant principals promote greater student achievement gains. This suggests that principals learn key aspects of effective school leadership during their assistant principal experience. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]