Mathematical Writing by Don Knuth, Tracy Larrabee, and Paul M. Roberts.
From the course catalog:
CS 209. Mathematical Writing—Issues of technical writing and the effective presentation of mathematics and computer science. Preparation of theses, papers, books, and “literate” computer programs. A term paper on a topic of your choice; this paper may be used for credit in another course.
Stanford University, Fall, 1987.
An admixture of notes, citations, examples, and war stories by several legends in the world of CS.
While making a number of serious points about writing, the materials are also highly entertaining.
I first saw this in Christophe Lalanne’s A bag of tweets / November 2012.