So i've been trying to find an the ideal case for mongodb, because I have to teach a nosql database to some people I am mentoring. I'm leaning heavily towards couchdb though. http://daemon.co.za/2014/04/when-is-mongodb-the-right-tool
Well, for teaching purposes, independent of suitability for a use case there are multiple courses available for free here: http://education.mongodb.com And, more node.js specific (but also offline capable, and available any time): http://mongodbschool.io/
the latter is especially useful. I'll pass it along to people for extra reference.