This book was really great for going over FaaS and walking through examples between the 3 prominent platforms (Google, Azure, AWS) without showing bias or leaning too heavily in favor of any one in particular (perhaps just a hair towards AWS). The focus is very much though on serverless function, and wont go over PaaS or how servers are abstracted out of the equation on platforms such as GAE.
The code/setup samples are in depth and you will leave with a sense of comfort for getting up and running with the basics.