There are a lot of good presentations from MongoNYC 2011 Conference. One of them that you can check out the slides from is: Optimizing MongoDb by Andrew Rollins.
One of the things you have to get used to about NoSQL is that its such a new topic that there aren't many resources out there for there - O'Reilly books, classes, etc. Its getting better all the time but its still a subject in its infancy. One great source of information you can tap into a couple times a year are the conferences that are put on for NoSQL. In fact, my first real exposure to the technology was at the NoSql East 2009 Conference. I highly recommend checking out the site for - its still got logs of relevant videos and slideshows showing how some of the biggest companies (Twitter, Facebook, Microsoft, etc.) are using NoSql to handle their needs.
Cheers,
TheSortedProgrammer
