The development of communication is a fundamental part of early childhood. Yet many students with disabilities require supports such as augmentative and alternative communication to develop communication skills. Teachers and paraeducators play key roles in supporting communication for these students, but often lack effective and accessible training options that include relevant content, active engagement, and application with individualized coaching. To meet this need, we engaged in iterative development, revision, and testing of the "POWR Training System," an online training and coaching program for teachers and their paraeducators. As part of a multi-year, federally funded grant, this iterative process was informed by feedback from educators and experts as well as by outcomes for paraeducators, a teacher, and children in a series of nonconcurrent single case studies. A description of the iterative process, outcomes for paraeducators, a teacher, and children as well as feedback related to the program are described. Future research directions are discussed. [This is an online version of an article published in "Journal of Special Education Technology."]