The purpose of this study is to explore the literacy practices members of an online fan community engage in to participate in the space and to question what learning happens through that participation. This dissertation is the product of a two-year virtual ethnographic study of The Sims Writers' Hangout (SWH), a discussion forum website established by fans of The Sims to support members' interests in creating and sharing Sims fan fiction. Affinity space theory informs an understanding of SWH's organization, and a definition of literacies as situated, social practices also frames the study. Data were collected following a discourse-centered online ethnographic approach, which guided systematic observation and interactions with eight key informants. The data corpus includes hundreds of pages of discussion forum posts, member profiles, moderator-created norming texts, numerous digital, multimodal Sims fan fiction texts, virtual interview responses from informants, field notes, and additional virtual artifacts, such as informants' websites and Flickr® photostreams. Study results are presented within three separate manuscripts prepared for publication and presentation, each exploring different lines of inquiry related to SWH. Chapter 3 focuses on tensions visible in the forum discussions to argue for an expansion of affinity space theory that accounts for the “hanging out” members do in the space. Chapter 4 analyzes one informant's literacy practices using a Design perspective. This analysis reveals the collaborative nature of Sims fan fiction literacies. The final manuscript (Chapter 5) offers an analysis of SWH pedagogy using Bernstein's pedagogic device concept. Data illustrate how pedagogic discourse in this online, informal learning space aligns with and challenges Bernstein's theory. Finally, Chapter 6 offers conclusions about how these three analyses expand our understanding of adolescent literacies and 21st century learning. This chapter also contains implications for theory and practice, recommendations for future research, and reflections on lessons learned.