A resource unit is a type of material that teachers use in pre-planning that provides a reservoir of teaching content, objectives, and learning experiences. It is important as it promotes teacher growth, acts as a form of pre-planning, helps evolve several learning units, handles individual differences, and suggests teaching and learning materials. The key steps in constructing a resource unit are to determine the title, introduction, general objectives, content analysis, activities, teaching materials and sources, evaluation procedures, and editing.