Hi there 
we are students in geoinformatics (second semester) and we need some help. We need for our project a map of the administrative districts in Bugaria. The main idea is that there schould be empty space in the borders of every district, so we can add a pie diagramm.
Thanks a lot, guys!
Best regards
There are indeed such borders for any country in the world, some are nearly complete, some are still missing in detail when you go more in detail of each country.
There are some sites displaying administrative boundaries:
http://www.flosm.de/en/index.html → administrative boundaries
http://openmapsurfer.uni-hd.de … but is currently not working
http://wiki.openstreetmap.org/wiki/ITO_Map … but not featuring boundary relations itself … only displaying the raw ways which are tagged as boundaries … but a river can be a boundary, too, therefore the need of relations.
You should also get familiar with OSM and its data elements first, if not happened yet. Start reading the OSM wiki … or sites like http://learnosm.org
After that go to help.openstreetmap.org and do a search for keywords like boundary, borders, administrative and similar … there are several ways how to filter the boundary elements from all other raw OSM data, and then how to display or render them.