I have given much thought to how a good manual should be structured; obviously I have tried to follow them when writing the Studio manual. In short:

• The text should be as concise as possible so that the reader to see as much as possible at a glance and without having to turn the page. A manual is not the place to be entertaining and verbose. (And yes, I do know that the XX for Dummies books are extremely successful, and I will never understand why.)
• Visual signals — including running pate headers — should be used to facilitate the navigation in the book and make it easier to remember the look of any particular page.
• Ample use of screen dumps makes it easier to use the book without the computer and facilitates the understanding of the functions described.
• The contents should be structured based on how the program is used, not how it is structured by its developers. I.e. functions that to the user are logically related should be dealt with together even if they are handled in different areas in the program; and functions which to the user are not logically related should not be dealt with together even if they happen to be placed in the same program dialog.
• Cross references should be used whenever justified; they are not terribly intrusive (and they should of course be “clickable” in a PDF file).
• A comprehensive index, preferably with linked page references, is absolutely necessary.
• A “Contents at a glance” section is good to have when the full contents section is extensive.
• A bookmarks list with immediate links to the sections of the book is helpful.

Furthermore, the typography should be reader-friendly – i.e. not only “look good” (without being intrusive) but also the typeface of the main text should not be too small (or too big), and the text columns not too wide (sadly, a very common fault).

If you feel I have been lacking in fulfilling these requirements, please let me know. (Or if you disagree with any of them.)