A few weeks back, Refaat and I spent the day in the studio recording a set of training modules on Nano Server. Since we had more time, we were able to go deeper in the content and demos than we have in our conference sessions. We also broke it into 12 modules so it is easy to consume and so as Nano Server evolves we can replace specific modules with new content.
Matt McSpirit who is Mr Virtual Academy wrote a nice intro that includes links to other Nano Server resources on his blog.
The Nano Server Microsoft Virtual Academy course is available here.