I recently started playing around with NoSQL databases as became interested in MongoDB. Here is a great video tutorial that will get you quickly introduced to NoSQL and the MongoDB application. It covers how NoSQL is different from typical RDBMS platforms and schemas, and how data is stored in MongoDB.
Permanent link to this article: http://ericsilva.org/2012/07/11/mongodb-and-nosql/
Permanent link to this article: http://ericsilva.org/2009/01/25/quickly-create-indexes-on-foreign-key-columns/