For TDD on the Web:
www.junit.org
www.testdriven.com
There are several useful texts, including
Test Driven Development: By Example by Beck,
Test Driven Development by Astels, and
JUnit Recipes by Rainsberger.
For refactoring on the Web:
www.refactoring.com
c2.com/cgi/wiki?WhatIsRefactoring (a major Wiki on many subjects)
The classic code-level refactoring text is
Refactoring: Improving the Design of Existing Code by Martin Fowler. Also excellent, at a higher design level, is
Refactoring to Patterns by Joshua Kerievsky.