Refactoring by Martin Fowler. He takes you through a piece of code and refactors it all into smaller and more usable parts explaining what he's doing along the

Refactoring by Martin Fowler. He takes you through a piece of code and refactors it all into smaller and more usable parts explaining what he's doing along the way. He does this with two difference pieces of code, if I recall correctly, then the third part is an index of all possible refactors. I read it cover to cover in less than a week and has totally changed the way I program.