This session offers an overview of research on why the early acquisition of broad content knowledge is crucial to young children's later academic success, and provides a guide so that the design, choice, and use of teacher training materials is improved by careful focus on content suitable for three and four year olds. The presenters will discuss these findings and what they mean for the improvement of professional development programs for early childhood educators, and will offer examples from four new research-based teacher training modules in the content domains of oral language development, early literacy, mathematics, and science.