redactor-rails has a advantage like no need to see preview of html contents.
Add to your application.js:
//= require redactor-rails
Add to your application.css:
*= require redactor-rails
and in your input field need to add a class: "redactor"
You can integrate carrierwave with this to save images in apFor more see documentation :https://github.com/SammyLin/redactor-rails