How to read org-mode documentation inside Emacs?

I installed Emacs 24.3.1 (using `homebrew`), which already comes with `org-mode`, but I can't find the documentation for `org-mode` within the Emacs built-in documentation (accessible via `C-h i`). I can find the `org-mode` docs online here, but I'd prefer to read it directly in Emacs. I find it very strange (in fact almost antithetical to the whole `org-mode` text orientation) to find myself having to read this documentation using a web browser, and not right inside Emacs. Do I need to download and install this documentation separately in order to read it within Emacs? If so, where can I find the appropriate (texinfo?) files? Or is this documentation already bundled by default with Emacs (and I just need to configure my current Emacs installation to be able to browse it through `C-h i`)?