The English version of this knowledge base is still in development. If in doubt please don't hesitate to contact us.
For a start, you may want to read about how to join the DFN-AAI.
The DFN-AAI metadata administration tool can be found at https://mdv.aai.dfn.de/login/.
The DFN-AAI Metadata Viewer provides an overview the participating home institutions and the available service.
The credentials will be sent directly to the new metadata admins.