Since joining fourTheorem earlier this year I've worked with AWS and the Serverless framework a lot, here are some of the best learning resources I've found:
The guide details how to set up a fullstack note-taking webapp using Lambda, DynamoDB, Cognito, Amplify, and S3. The project uses React, but the important bits are explained clearly enough to be followed along with any frontend framework. The guide even sets up a billing system with the Stripe API, making it a great way to prototype a potential business project very quickly.
The videos are concise, use best practices, and usually come with a git repo in the description which is very helpful. Complete coding is always the first place I go to when I need to refresh my understanding of anything AWS or Serverless.
While Serverless Stack's guide sets up some services such as cognito through the AWS console, SLIC is configured entirely by code. By using this "Infrastructure-as-Code" approach, the project can easily be version controlled, deleted, or deployed on another AWS account.
I find that SLIC is a great resource for seeing how certain best practices should be done in a serverless way:
SLIC starter was created by the team at fourTheorem and it's open source so contributions are welcome by everyone!