How to create forms similar to admin block forms
Here you have two examples to learn how to build a custom module with drag and drop elements:

http://coffeeshopped.com/2010/09/drupal-drag-and-drop-tables-in-custom-modules

http://www.computerminds.co.uk/quick-guide-using-drupal-add-tabledrag-and-enjoying-jquery-drag-and-drop-loveliness

Oskar