This study was designed to enhance early childhood teachers' efforts to prepare young children for school. Thus, the first objective was to determine if teachers receiving comprehensive professional development (i.e., PD) would show gains in language and literacy instructional practices than teachers randomized to the control condition. Objective 2 was to determine if teachers in the second year of the intervention showed greater gains in their instructional practices than teachers receiving the program for one year and whether gains in child outcomes were greater if they had teachers with 2 years versus 1 year of the program. Finally, as the study design had Year 1 control teachers becoming intervention teachers in Year 2, objective 3 was to determine if across the same randomly selected teachers with and without the intervention there were greater gains in both teacher practices and child outcomes in year 2. Professional development included an on-line PD course with mentoring, the use of a technology-driven progress monitoring tool, and a research based curriculum. Results show evidence that these components are effective in promoting greater change in the teachers' practices when compared to the control teachers (Objective 1). Greater gains with moderate to large effect sizes were found for the program teachers in the initial 4-month training period across most Teacher Behavior Rating Scale (TBRS) subscales. Some of the greatest gains were found in school readiness instructional activities. Although the amount of time a teacher participated in the program was expected to result in differences in instructional practices, no differences were found. Differences in the teachers' exposure to the program were apparent when examining the children's development of language and early literacy skills. While a positive effect of additional teacher participation was seen for all skills, at times these were dependent upon the child's age and language of assessment. The two aspects of emergent literacy have been found to be unique predictors of reading from the recently released National Institute for Literacy report (2008), also showed greater increases if children's teachers were in their second year of the program. For letter-sound correspondence this finding was strongest for children who were younger while print discrimination skills were strongest for children learning English. The effect of amount of teacher participation also was seen for phonological awareness skills. However, unlike the other outcomes, those children who were older at the beginning of school and their teachers had more experienced with the program showed the greatest gains. This may occur because of the complexity of phonological awareness, such that a more experienced teacher is better able to implement these types of activities. Finally, the design of this evaluation allowed for comparison of a small group of control teachers in year 1 and again as year 2 program teachers. The differences in these teachers' instructional practices before and after the program were found in almost all areas of teaching and the improvements were strong. The different groups of children in these teachers' classrooms also showed differences in their language and emergent literacy gains across the school year. As the 11 community partnerships all had Head Start, public school, and child care classrooms, this study demonstrates that comprehensive professional development, mentoring, progress monitoring, and collaborative relationships between educators can result in benefits for at-risk children. The results can inform state education policy by demonstrating the need for a comprehensive approach to preparing teachers in early childhood classrooms in order for children from low income homes to show growth in language and early literacy skills. (Contains 4 tables and 5 figures.)