Barbara E. Walvoord, Assessment Clear and Simple: A Practical Guide for Institutions, Departments, and General Education (2d ed. 2010). I am a big fan of this book. As the title suggests, the book presents assessment in a straightforward manner. It cuts through the jargon to focus on the essentials of outcomes-based assessment. Chapters present information specifically for faculty, department chairs, and deans other leaders. This is a great resource for someone brand new to assessment.
Barbara E. Walvoord and Virginia Johnson Anderson, Effective Grading: A Tool for Learning and Assessment in College (2d ed. 2010). An excellent resource on course-level assessment to promote student learning. There are also tie-ins to departmental and programmatic assessment.