Windows 10, Inform 7
Where to put image files (what directory).
I recommend working with just text at the start but if you want to learn more about Inform 7 and images here are a few places to start.
See Chapter 23.4 Gathering The Figures in the Writing with Inform documentation. This gives some basic information about figures, i.e. images. Note: The documentation might also be available in the Ubuntu Inform IDE Documentation tab (if it has one).
To do anything more elaborate you might have to use an extension. There are several for for Glulx, a 64-bit version of the Z-Machine (I haven’t used any of these yet).
There is also set of Vorple extensions that might be useful (also haven’t used any of these yet).
A search of the forum using “inform 7 images” might turn up additional information.
There is an online Inform 7 Extensions Library if your IDE doesn’t let you install from within it.
There is also an online editor called Borogove which lets you experiment with various interactive fiction tools (in case the Ubuntu Inform 7 IDE isn’t to your liking).