How to fetch data from already saved nodes to the edit-form for node creation?
SOLVED: 

Via http://drupal.org/node/1028952#comment-3968840 i found this little module 

http://github.com/Itangalo/Node-creation-block--Drupal-7-

that resolved my issue.

Another possibilty (although in dev-status) is the use of this module: http://drupal.org/project/formblock