This guidebook is designed to support state and local leaders in the first step in the improvement process, the development and facilitation of a needs assessment. The guidebook does the following: (1) Reviews some of the major school-improvement-related needs assessment requirements found in the Elementary and Secondary Education Act of 1965, as amended by the Every Student Succeeds Act; (2) Introduces the elements of a successful needs assessment; (3) Presents a practical approach to addressing those elements across the phases of needs assessment implementation; (4) Describes supports that states can provide to districts, and districts to schools, in the implementation of effective needs assessments; and (5) Discusses the role of needs assessment within a continuous improvement process.