After a colleague asked about this, my interest was primed on quantum computing. I found wikipedia hard to follow and the textbooks were really expensive. Then I stumbled on this course by IBM:
https://quantum.cloud.ibm.com/learning/en/courses/basics-of-...
It has prereqs in complex numbers and linear algebra, but is quite easy to follow if you have these.
I like how it first uses quantum notations to describe the non quantum world, so you get used to the reasoning. Then it adds the actual quantum stuff on top of the now understandable reasoning.