Although many studies have explored shared book reading between preschoolers and their families, very few have examined this practice within a large, nationally representative sample. Using the ECLS-B dataset, this study investigated shared reading among nearly 700 families of diverse ethnic, linguistic, and socioeconomic backgrounds. Coding of families' book-related discussion focused on the variety of types of talk that parents used during reading. Results showed that parents focused primarily on the meaning of the story, with little attention to the code of the text. The range of talk techniques that parents used was largely independent of background factors such as child gender, ethnicity, or age, as well as family home language. A wider variety of meaning-related remarks by parents was linked to more advanced language skills among preschoolers. Findings provide a portrait of the nature of shared book reading discussion among American families, a profile of the background factors that are linked to this talk, and a precise account of the unique contributions of this talk to key emergent language and literacy competencies.