I'm looking to create maps of administrative boundaries. Sometimes nested. For example I want to create shapefiles or geojson-files for all the countries in the world, including states in the US and counties in Texas. Searching on gis.stackexchange mostly pointed to http://overpass-turbo.eu. But overpass looks like it's geared to interactive usage. Furthermore the software has to run on my own server.
Being a newbie to gis and mapping software, any pointers to books or blogs or whatever that could help me would be welcome too.
Best,