John W. (Governors State University, University Park, Illinois, USA) Swain & Kathleen Dolan Swain 
Effective Writing in the Public Sector [PDF ebook] 

Intended for both students and practitioners in public administration who want to communicate more effectively with a variety of audiences, this book offers clear, easy-to-understand guidelines on how to write more clearly, concisely, and coherently, as well as correctly. It covers the basics of good English and applies those basics to general forms (such as memos, letters, and e-mails) and more specific forms (such as newsletters, proposals, budget justifications, and rules) used in the public sector.