Getting Started with Cloud Firestore on the Web
What is a NoSQL Database? How is Cloud Firestore Structured?
Getting Started with Cloud Firestore with NodeJS
Model Relational Data in Firestore NoSQL
Lets learn more Firestore - Maps Arrays and Subcollections
Started Tech Buzz
More data structures and rules about how to model your data using Firestore by Todd Kerpelman, an awesome developer advocate from Google.