I wish I had time to write a decent post. Lacking time, I'll try to be concise. If you want to really understand the benefits of TDD, the best book I know on the subject is actually Michael Feathers, "Working Effectively with Legacy Code". It is rather dense and getting a bit dated, but by showing you what you need to do to improve legacy code in a methodical fashion, he provides the basis for learning how to do good TDD.
Its a good book but from my memory it doesn't really address solutions to whats being discussed in the post, and I'm presuming the author is familiar with the book because he discusses characterization tests.
