EU citizens do not need a visa for entering Germany.
Since the entry into force of the Freedom of Movement Act/EU on 1 January 2005, EU citizens are no longer required to apply for a residence permit after entering Germany. However, they need to register, like everyone else, with their local residents registration office.
More information for foreign nationals interested in working in Germany is available on the websites of the Federal Ministry of Labour and Social Affairs and the Federal Employment Agency.
Federal Ministry of Labour and Social Affairs
Federal Employment Agency