Martin Noutch, author of the wonderful Steam Highwayman books, is a true scholar of the craft of gamebook writing. One of the reasons his own books are so good might be because he has thoroughly analyzed the works of other writers in the field. The shoulders of giants and all that.
So that you can benefit from his studies too, Martin recently posted his story maps of the Fabled Lands books. Looking at those prompted me to dig out some of the maps I used to plan the books. Astonished that I still have this stuff after 30 years? I'm working on that hoarding obsession.
Trust me when I say that you haven't seen the full possibility of storytelling married to open world gamebooks until you've played the Steam Highwayman series.
And if you like the idea of steam-powered vehicles and picaresque adventures in an early 19th century setting (or style thereof), I recommend Keith Roberts' seminal SF novel Pavane. (It is SF, incidentally, and not steampunk, which is really a branch of fantasy because physics, but I don't want to give any spoilers. Read it and see.)
