Howto drag & drop field images in editor
Insert is a utility that makes inserting images and links to
  files into text areas or WYSIWYGs much easier. It adds a simple
  JavaScript-based button to FileField and ImageField widgets. When used
  with ImageField and ImageCache, images may be inserted into text areas
  with a specific ImageCache preset.




2) Vimeo Screencast Colorbox for Drupal 7, part 2: Inline images with the Insert module