Gregory Brown, Steve Klabnik, myself and members of the Ruby Mendicant University have been beginning to put together a Ruby Documentation Team.  To start, we've created https://github.com/ruby-doc and are looking to fill it in with information about how to contribute documentation for ruby.

For the present we intend to focus on creating a website that documents the process for creating doc patches for Ruby using tools english-speaking rubyists are familiar with ( git and github) and having reports showing high-priority targets for documentation.  We'll also be looking to use the ruby-doc / ruby-lang.org mailing list for coordination.

At some point in the future we intend to merge this effort back into ruby-lang.org and https://github.com/ruby.

Additionally, I've added a Documenter How-To page to the redmine wiki:

http://redmine.ruby-lang.org/projects/ruby/wiki/DocumenterHowTo