I'd recommend the following (it worked for me):
- Install Grunt and get your first sample grunt task running based on the Grunt documentation
- Use this grunt task to get server-side Grunt running Mocha tests for you, and this one for client-side tests. From the command line, you can just run
$ grunt
to watch the results pop up. - At this point, you can check out Mocha interfaces for samples of how your tests can look. Note that there's also should.js, if you're big on rSpec-style tests. Once you've settled on an interface, more Googling/StackOverflowing is the best way to proceed (e.g. Google "Mocha should.js examples").