I’m taking part in the Rails Guide Hackfest which is “an attempt to improve Rails documentation and make the barrier to entry as low as possible.”
You can take a look at it here: http://guides.rails.info/securing_rails_applications/security.html
If you find a typo or if you’d like to contribute, the Lighthouse ticket is here:
http://rails.lighthouseapp.com/projects/16213/tickets/7