Online resources:
- The Catsters channel
- MATH198 course notes (ongoing)
- MAGIC course
- Barr, Wells: Category theory for computing science
- Jaap van Oosten - basic category theory
- Tom Leinstner
- Eugenia Cheng
- Steve Awodey - very similar to the book mentioned by Quadrescence
- Daniele Turi
Books:
- "Basic category theory for computer scientists" by Benjamin Pierce
- MacLane - solid mathematical foundations, but hardly any references to computing