Start with place, time and jurisdiction
Find the exact town, parish and historical state before searching a surname. Germany has no single nationwide genealogy register, borders changed repeatedly and the same place name may occur in several regions. Use gazetteers and historical maps to identify the responsible Standesamt, church archive, municipal archive or state archive.
Follow the strongest record sequence
Civil registration generally leads research in later periods, while Catholic, Protestant and Jewish registers extend earlier lines. Archivportal-D helps locate archival descriptions across institutions; Matricula provides selected church books. The Federal Archives is most useful for particular twentieth-century federal, military and persecution-related records, not ordinary local civil registers.
Preserve evidence and local context
Cite the repository, locality, denomination or civil office, register type, volume, entry number, page or image. Preserve German script and original place names alongside modern equivalents. Data protection and archive rules vary, so document access restrictions and do not infer a family link from a matching surname alone.