What are some good introductory books on Galois connections? I have read Galois Theory from Emil Artin, Algebra from Saunder Mac Lane, and I'm starting Serge Lang.
Steven Roman's book Field Theory treats the Galois Theory part of his book using Galois connections. I don't have the book but I had browsed through it one time when I was looking for a different book in my university library, and I have to say that it seemed pretty good.
In particular, take a look at chapter 6, where he develops some theory about Galois connections and applies it to study the Galois correspondence.