There is not much docs about this, but watching this video
https://www.youtube.com/watch?v=DJQnDZCbUHk
will help you with testing your drupal site and RESTful WS and Advanced REST Client.
For more info, look this one
https://www.youtube.com/watch?v=a2nHIWlCXSw
has all the drupal service modules in it and good examples how to use them.
One big GOTCHA is that.
X-CSRF-TOKEN is working on my localhost as
X_CSRF_TOKEN (MAMP) but when I tried to use it with remote server, where I have CentOS and Nginx installed it didnt go through until I made it as X-CSRF-TOKEN. I kept getting 403 errors.