We put together some quick screencasts to make it easier for people to get started with MirageOS. They're all in a playlist below, which is around 10 minutes in total.
There are currently 4 videos which walk through some of the typical steps. The first three cover installation, building a 'hello world', and building a Xen unikernel on an Ubuntu machine. The fourth video gives an overview of the development workflows that are possible with OPAM and Git.
These should give everyone a clear idea of what it's like to work with the tools before leaping in and installing things!