CC BY-NC-SA 4.0
Most of my materials are original works.
This licence means that other people can copy the works and can modify them. But cannot use them for commercial purposes. If they modify or make derivative works, the licence remains the same.
I am happy for other people to use my work to incorporate into their own course, as long as it is not for commercial use, in which case I would invite them to collaborate with me.
I will be using other sources from the internet, and I will reference them fully.
Read here for human readable details of this license.