Configure CKEditor - WYSIWYG HTML editor What is the way to configure CKEditor - WYSIWYG HTML editor for Drupal 7 sites?
You can install the CKEditor module for Drupal for that: http://drupal.org/project/ckeditor

You will have to include CKEditor by yourself, which you can download from here

Install the Drupal module and put the ckeditor folder from the second link under sites/all/libraries and that should be it.