What’s the Point of TDD?
Here's an article introducing test driven development which is short enough that even the busiest developer can find the time to read.
The point of TDD is to drive out the functionality the software actually needs, rather than what the programmer thinks it probably ought to have. The way it does this seems at first counterintuitive, if not downright silly, but it not only makes sense, it also quickly becomes a natural and elegant way to develop software.