This report represents the first milestone of a work in progress. That work is a comprehensive handbook on how to produce high-quality documentation for software architectures. The handbook, tentatively entitled Software Architecture Documentation in Practice, will be published in mid- to late-2000 by Addison Wesley Longman as a book in the SEI series on software engineering. Aimed squarely at the practitioner, the handbook is intended to fill a gap in the literature: There is a complete lack of language-independent guidance about how to actually capture an architecture in written form so that it can fulfill its purpose as a communication vehicle providing a unified design vision to all of the varied stakeholders of a development project. The theme of the work is that documenting an architecture entails documenting the set of relevant views of that architecture, and then completing the picture with documentation of information that transcends any single view. The report lays out our approach and organization for the complete book, and provides full guidance for one of the most commonly used architectural views: the layer diagram. The audience for this book is the community of practicing architects, apprentice architects, and developers who are on the receiving end of architectural documentation.