In this article, the authors propose four principles to guide teachers' thinking as they use technology to support teaching and literacy learning in 21st century classrooms. Specifically, teachers must be aware of emerging technologies, recognize the complexities of new literacies, realize tech-savvy students may not be skilled readers and writers of web-based texts, and develop assessments to evaluate 21st century skills. Keeping these principles in mind will help teachers prepare students to become effective readers and writers of digital texts.