In principle, EU nationals, as well as nationals from Iceland, Liechtenstein, Norway and Switzerland, can enter Germany. Freedom of movement rules allow them to work without restriction in Germany.
Nationals from Australia, Israel, Japan, Canada, South Korea, New Zealand and the USA can also enter Germany without a visa. However, they must apply for a residence permit promptly once they have found employment in order to be permitted to work in Germany. Please contact the Foreigners Registration Office (Ausländerbehörde) in your local district or town about this.
All other nationals must obtain a visa from the German embassy in their home country before entering the country.