This is the best discussion that I have found on couchdb native views. They are still a hidden feature of couchdb and there are not many people who use it.
To summarize the discussion in the link
Erlang views are significanly faster than javascript views. But there could be security implications since they run natively and are not sand boxed like javascript views.
There are not many tutorials because there is not much to learn about them. They are just like normal couchdb views translated into erlang. If you gave an example of your view maybe we could help you translate it into erlang but you will have to learn the basics of language if you want to write your own views in it.
I am trying to figure out if there's anything else I need to install to run these such as erlang itself
Nothing. Every thing you need is provided by the couchdb itself.