A list of free online resources to help you in the course, especially tutorials to introduce/refresh your knowledge of the concepts of various frameworks, languages, etc.
There are three types of helpful resources linked here.
Tutorials give you a quick conceptual introduction to a package, technology, etc., without going into great detail on everything it can do.
Reference guides are official and detailed documentation about libraries, packages, etc. that may be useful to get familiar with more detail and what else is possible once you have grasped the basics.
Cheat sheets are very concise reminders of how to do things you already know how to do but sometimes forget the exact syntax, arguments, etc.
Try the actual tutorials (links at top of this page) if you want a refresher on the concepts behind each framework.
Capybara cheat sheet by example—most of your questions about writing and running Cucumber scenarios will really be about Capybara, the framework that "pretends to be a user" and can manipulate web pages.