I recently heard about braid theory and read the Wikipedia article on it, and it seems really beautiful. What is a good resource for learning more about it?
I have a background in mathematics at the undergraduate level—I took introductory courses on combinatorial topology and abstract algebra (I definitely found the latter quite difficult).
There are a few ways you can approach the subject. I personally went via the algebraic topology route which you may find useful if you know something about the fundamental group/manifolds/higher homotopy groups. I wrote a little about a few resources (definitely not exhaustive) here. The first two references are algebraic topology-based. The third, more accessible and elementary, reference only relies on a background in a small amount of group theory and linear algebra.
For your convenience I'll leave those references below: