The requested URL was not found on this server

If there are any issues related to the Pressbooks portion of the installation we are happy to add/improve them. It sounds like the trouble you were having was with the initial WordPress Multisite installation, and it is not practical for us to maintain a parallel set of documentation to the WordPress project especially given that WordPress Multisite installation varies from server to server (Apache/Nginx/etc). Glad you got it worked out!