Google offers two G Suite accessibility guides. There is a guide for administrators and there is a guide for users.
The G Suite user guide to accessibility is designed for end users. The user guide is divided into sixteen sections. In the first section you will find recommendations for the best screen readers to use while using G Suite on Mac, Windows, and Chrome OS computers. The other sections of the guide are devoted to specific products within the G Suite including Google Classroom. Each section contains information on accessibility shortcuts, screen reader instructions for each app, and in some sections you will find how to videos like this one for using a screen reader with Google Docs.
The G Suite administrator guide to accessibility covers much of what you will find in the user guide, but also includes recommended settings to apply within your Google Apps admin console.