The following is a narrated video that walks through how to use Google Read & Write with PDF's. It demonstrates the basic features and and briefly explains why it is beneficial for all learners.
The link below takes you to an easy to use Reference Guide for Google Read & Write:
https://www.texthelp.com/Uploads/MediaLibrary/texthelp/US-Training-Documents/Read-Write-for-Google-Chrome-Quick-Reference-Card.pdf