Docbook.. (again) (Score 4, Informative)

I have seen a variation of this question at least two times posted here. The unanymous answer is usually docbook and in this case is more relevennt, since the document is technical in nature.

good pick is DocBook: The Definitive Guide written by Norma Walsh (who chairs the Oasis DocBook Technical Committee) and published by O'Reilly that. Of course the book is also available in HTML, PDF and plain text.