Sample books?

[Buddha Buck]

Are there any samples of reasonably detailed books out there? Something
that could be used to try out gnucash features without having to do a lot
of data entry first, or that people could be pointed to along the lines of
"go and download 'personal-sample.gnucash' and look at the Mortgage
scheduled payment for an example of how to do what you want"?

If not, does such a thing sound useful to generate and make available?