If you've been hearing more and more about unit testing your applications but aren't sure where to start, you might want to check out this post from Jani Hartikainen. It's the first in a series looking at what unit testing is and how it can help keep your applications running smoothly.
In this post I’ll introduce unit testing: What it is, when it’s a good idea and when it might not be. I'll also discuss a bit about what makes for a good unit test. Next week I'll post a followup to this, which will be more about actually writing unit tests with examples.
He introduces the topic in three parts - what unit testing is, when its a good idea and what to think about when writing up tests to make them good.