The GraphQL Guide is a book by John Resig, the creator of jQuery, and Loren Sands-Ramshaw. At 883 pages, it's a comprehensive text, including a beginner introduction, an overview of the spec, and advanced client and server topics.
This book is for most programmers. If you write software that fetches data from a server, or you write server code that provides data to others, this book is for you. It’s particularly relevant to frontend and backend web and mobile developers. If you don’t know modern JavaScript, we recommend learning that first, but it’s not necessary. For example, if you only know Ruby, you can likely follow the JavaScript server code in Chapter 11 well enough to learn the important concepts of a GraphQL server, most of which will apply to using the GraphQL gem in your Ruby server code.