There are tutorials, and up to about 2007 there was a Simply Accounting 'Accounting Manual' that was also a sort of tutorial.

Outside of the 'Getting Started' and other help, there is no manual.   If you find a 'Missing Manual' book, it's probably for the U.S. / Peachtree / Sage 50 software.

I have copied from some previous suggestion by someone with the hope it still works:

Everything that was in the manual has been moved to the online help.   It's the way the industry is going

All the manuals and setup guides issued in the past 5 years or so are here:

www.simplyaccounting.com/.../guides_and_manuals

The online Help is the closest we have of a manual. As previously stated this is the way all software is being documented today. There are four volumes of training material covering all aspects of the program but not in depth. This training material is for users on a daily basis after they have completed the four days of training. I believe they can be purchased through SageU.