This document outlines a 21-session unit plan for teaching explanatory writing to third grade students. The plan includes immersion activities, minilessons on various writing skills and techniques, individual writing time, and conferencing. Students will generate ideas, conduct research on a topic, take notes, draft and revise their writing using text features, facts, quotes, and leads. They will learn skills like paraphrasing, citing sources, and using an editing checklist. The unit culminates in a celebration of completed student essays.