Xen.org recently published a revamped edition of its official training slide deck titled Introduction to the Open Source Xen Hypervisor, available under the Creative Commons Attribution-Share Alike 2.0 Generic License.
Unfortunately the 154 slides don’t have footnotes and there’s no audio, but it’s still a welcome effort to simplify the evangelization of the hypervisor that powers half the virtualization platforms available on the market (Citrix XenServer and Oracle VM Server/Virtual Iron).