This article bridges research to practice by summarizing an interactive content-enriched shared book reading approach that Spanish-speaking parents of preschool-age children can easily use in the home to accelerate content vocabulary knowledge in Spanish. The approach was implemented in preschool classrooms using a transitional bilingual education model in Central Texas and in a Saturday Spanish heritage language school in the Midwestern United States. Spanish-speaking emergent bilingual children from both lower and higher socioeconomic status backgrounds learned content-related vocabulary via parent-child discussions of Spanish storybooks and informational texts organized by compelling science and social studies themes and topics. The authors provide recommendations for how teachers can support Spanish-speaking parents' ability to develop informal knowledge-building experiences through home-based interactive book discussions in Spanish.