Suggest the native current theme-mechanism

load-theme is the build-in support for Emacs 24.  Color-theme is a
third-party package, not available in Vanilla Emacs
Add link to the Org-mode website

It's pretty informative.
Add info on how to install packages in Emacs 24
Add Emacs planet to resources
Use em-dashes instead of plain hyphens
Merge pull request #11 from pank/gh-pages

Additions and stylistic changes.