Lecture-Tutorials for Introductory Astronomy, which was developed by the Conceptual Astronomy and Physics Education Research (CAPER) Team, is a collection of classroom-tested activities designed for the large-lecture introductory astronomy class, although it is suitable for any astronomy class. The Lecture-Tutorials are short, structured activities designed for students to complete while working in pairs. Each activity targets one or more specific learning objectives based on research on student difficulties in astronomy. Most activities can be completed in 10 to 15 minutes. The instructor's guide provides, for each activity, the recommended prerequisite knowledge, the learning goals for the activity, a pre-activity assessment question, an answer key, suggestions for implementation, and follow-up questions to be used for class discussion or homework.