What we know
Using Marble Springs
Marble Springs 2.0 had a great deal of convoluted instructions, for a variety of reasons (people did not know how to use a computer, let alone a complex jerry-rigged spaghetti monster programming job we did on HyperCard to get HyperCard to do things no one had thought of…)
So, you are lucky. These instructions are still a bit convoluted, but much easier.
Reading Marble Springs
You don't need instructions here, only a hint: if you have a class project or want to analyze, just pick one character and read through their links and stories to find out who they are. The story the author ascribed to them is not anywhere near the entire story.
Writing Marble Springs
Follow the Wikidot Handbook. Connections, humans, places, and meta-content pages are all in templates (Thank you Rob Elliot!) and should be relatively easy to follow.