September is the most important month for teachers. It's a decisive moment for them to organize (even though this should have been a previous work), meet their students and face new teaching challenges. This is the perfect opportunity for learning about open resources that could be helpful.
I'm currently teaching Linux/security in exchange of self-defense classes. I really wanted to use a shared document without counting on Google and I decided to use a disroot pad; we are getting along so well with it, it allows basic editing, comments and it's easy to use.
If you are teaching any computer science subject, using gitlab is a really nice resource. I had a teacher at university that used this method and forced us to learn about testing, pull request and git. This is a real-life experience as well as handy, because you can take advantage of the Kanban board as well.
For creating a public book list that your students can take a look at, I suggest inventaire and incipient, yet easy to use, webapp for making a library.
Of course, using a Linux OS is a must, for that some of the most user friendly are the classics: Mint, Ubuntu... also Elementary if you feel more comfortable in a MacOS-like OS.
I invite you to comment more examples that can be useful! T