Where can I learn more about refactoring?
A good place to start learning about refactoring is through Martin Fowler's book, Refactoring: Improving the Design of Existing Code. Martin also runs the Refactoring web site where you can find a complete catalog of the various refactorings covered in the book along with additional refactorings that weren't covered in the book.
Another place to look is the eXtreme Programming (XP) community. Refactoring is a core tenet of XP.