I think this could be one of the main challenges Elm face in terms of gaining support. I've been playing around with Elm the past week (creating a fun little web app to learn a new language) and the documentation would likely keep some developers from pursuing the language much further. What helped me was familiarity with functional programming via Clojure, and component based web apps with Om and React.

I think the docs could use a chapter on functional programming and how that works in the land of ML languages, and perhaps a few walk through examples of some simple, but not overly simplistic, apps.

So far though I think the language is pretty interesting, but I've yet to do anything really fancy with it.