What was the first "for Dummies" book ever published?

DOS for Dummies in November 1991

http://www.answers.com/topic/for-dummies

A book titled "Ventriloquism for the Total Dummy" existed in the 1980s,
by Dan Ritchard.


https://www.abebooks.com/Ventriloquism-Total-Dummy-Dan-Ritchard-Villard/31416293751/bd

The "For Dummies" series of how-to books was started by John Kilcullen for book publisher IDG Books with the book DOS for Dummies in November 1991, written by Dan Gookin about the computer operating system DOS. The story goes that a customer back in 1987 wanted a book that was simple and easy to use, as he considered computer books at the time dull and dreary reading. Next came PCs For Dummies, by Gookin and Andy Rathbone, propelling the series' popularity, along with The Internet For Dummies, by John Levine, Carol Baroudi, and Margaret Levine Young.

https://en.wikipedia.org/wiki/...For_Dummies

The For Dummies series began during 1991 with DOS for Dummies, written by Dan Gookin and published by IDG Books.

https://en.wikipedia.org/wiki/For_dummies_books#History

Dan Ritchard here --
Arpeggionist is correct.

The title of the book was based on a request by my publisher, Villard. They planned to include a puppet, in a bag, tied onto the book. They wanted a title similar to the book, "Juggling for the Complete Klutz" which also had an attachment, juggling balls. Based on limited words/sounds in English, I suggested the working title. Nothing better came up, so they kept it. I also suggested including a mirror, which was to be adhered to the book, and that was added to the bag, but without instructions on peeling and sticking it inside the cover.
I did a 9 city tour when my book came out for the gift season in early December 1987, and shortly thereafter the For Dummies series ran with the concept.

Here's a link for Ventertainer's answer.
https://www.amazon.com/Ventriloquism-Total-Dummy-Dan-Ritchard/dp/039475638X

However, I suppose the question refers to the series gdec1 and Zb mention.