David Golding has started to write an introductory book for CakePHP with the title “The newbie’s introduction to CakePHP”. As the title indicates, the book is aimed at newbies and so it covers the first steps with CakePHP. It is not completed yet, but I think it will become a great addition to the manual.
You can download a preview of the book as a PDF from David Golding’s website: http://www.davidgoldingdesign.com/newbie-cakephp.pdf.
Update 2007-07-31: There exists now a forum for the book.