Covering Spaces Self-Study

I am an undergraduate student having some background in Algebraic Topology. I am currently interested in Algebraic Topology, particularly, Covering Spaces. I have Munkres's book, Allen Hatcher's book for self studying. These are great sources, yet they are not that easy too.

So I am asking if there are other books, lecture videos or lecture notes suitable for self-studying on these subject, any notes for preparation for reading Munkres or Hatcher.

• I first learned about covering spaces from a little book called "Essential topology" by Martin Crossley. I found it accessible as a first book because it introduced me to the very intuitive example of $\mathbb R$ as a universal cover for $S^1$ without introducing the general technical machinery. I read Hatcher much later. – Kenny Wong Mar 13 '17 at 11:06