A few blog posts on "how to make your own guix!" would be really neat. I'm not as deep as I'd like to be, but roughly it's a simply a matter of outputting a derivation that `nix-daemon/nix-build` can handle, right?
I do want to add a section to the Nix manual that describes what it is (data model, key abstractions, etc.). Everything today is some variation on "how to use it".