From Good to Great—: The Finer Points of Writing User Documentation  

A few years ago, the NeXT user publications group was handed a charter to create casual books with personality. We were also told to condense the user documentation for an entire operating system and several bundled applications into 300 pages. And of course we had the top priority of creating accurate, complete, and easy-to-use documentation. To our delight, these goals ended up being mutually compatible. The keys? Task orientation, flat hierarchy, carefully crafted page design, illustration, and a casual, intelligent tone. We also broke some 'rules'! (Caution: Some of the following material may seem radical to seasoned traditionalists.)

Casabona, Helen. STC Proceedings (1995). Articles>Documentation>Software>Usability