Great way to learn new things is always to read docs. I tend to read during travelling as well, but then due to connectivity issues, I am limited to whatever I have locally on my Mac. I love docker and keep learning about it all the time i get.
Docker has great docs. For anything and everything docker has a docs page. What docker can do, what docker cannot, why it cannot, its all included.
Somethimes i wish i had its docs offline, now I can. Just run the following command and you are good to go.
docker run -it -p 4000:4000 docs/docker.github.io:latest
Ofcource, For this to work you will have to have docker installed, which If not already, you can find insttruction to install docker on this page.