I've struggled with the same so i wrote my own - https://smalldata.tech/blog/2019/06/08/docker-in-10-minutes

It's a bit dated now, but I found Using Docker by Adrian Mouat to be incredibly helpful.

http://shop.oreilly.com/product/0636920035671.do

I'd suggest "Practical Docker with Python: Build, Release and Distribute Your Python App with Docker" by Sathyajith Bhat.

Very beginner friendly.