Start from Vol. 3, then go back to Vol. 1 and Vol. 2:
- The Data Model Resource Book, Vol. 1: A Library of Universal Data Models for All Enterprises
- The Data Model Resource Book, Volume 2: A Library of Universal Data Models by Industry Types
- The Data Model Resource Book, Vol. 3: Universal Patterns for Data Modeling
References:
The Postgres document is a must read, if you are serious into improving your skills in database development. Most tutorials (books or videos) are only quoting the documentation back.