I think the best thing for a newbie to do is to tackle some code katas that lend themselves to unit testing. For example; validating an e-mail address. TDD becomes the natural flow once you've tackled a few of these Code Katas. Check out the following code kata for the e-mail address validator I mentioned: E-mail ValidatorE-mail Validator
For an explanation of what Code Katas are for those of you who don't know, check out the following link: Code Katas