Large general tutorial video making a directory with content types and views:
https://www.webwash.net/how-to-build-directory-using-drupal-8/

PathAuto module information. For helping to make more readable URLs
https://www.webwash.net/automatically-generate-url-aliases-using-pathauto-drupal-8/

Using Entity References in Views – Great overview of using entity references.
https://www.ostraining.com/blog/drupal/drupal-8-entity-reference-view/

Drupal 8 theme twig template file reference. Includes various naming conventions for pages, views, blocks, nodes, etc.
https://www.drupal.org/docs/8/theming/twig/twig-template-naming-conventions