TechWhirl (TECHWR-L) is a resource for technical writing and technical communications professionals of all experience levels and in all industries to share their experiences and acquire information.
For two decades, technical communicators have turned to TechWhirl to ask and answer questions about the always-changing world of technical communications, such as tools, skills, career paths, methodologies, and emerging industries. The TechWhirl Archives and magazine, created for, by and about technical writers, offer a wealth of knowledge to everyone with an interest in any aspect of technical communications.
Editing by Design, by Jan V. White, 2nd edition, New York:R. R. Bowker Co.,
1982. The author calls it "a guide to effective word-and-picture communication
for editors and designers." It deals specifically with magazine design, but
lots of the information is applicable to technical documents.