Node.js packages are usually small and self-contained. Without typing/APIs Node relies heavily on documentation, so packages which are not well-documented will fall into oblivion quickly. Who'd write a OSS library which nobody can use?
Mocha's docs are pretty awful, actually. If you don't know how to use it when you start, the docs are not going to help, much. They're mostly buzzwords and examples that show (in limited cases) "what", but not "why", and give you no purchase for answering questions about how to structure things.
Well, not all projects show off on video. IMHO, a video is a sloooow way to present information. I'd rather skim through some examples/demos/interactive docs.
My personal favorite, interactive docs!
http://coffeescript.org/
I like these ones because of the straightforwardness:
http://socket.io/
http://jade-lang.com/
http://mongoosejs.com/
And many more:
http://visionmedia.github.com/mocha/
http://meteor.com/
http://derbyjs.com/
http://compoundjs.com/
http://learnboost.github.com/stylus/
Almost all packages without a website have a README (npm spits out warnings if missing README):
https://npmjs.org/package/request
https://npmjs.org/package/browserify
https://npmjs.org/package/formidable
https://npmjs.org/package/forever