To attend to cross-border business, Jones Lang LaSalle has an office in Berlin. The things you notice about the city are its impeccable planning, its dignified grandeur, beautifully preserved architecture and bracing weather.
My favourite hotel is Swissotel. It is centrally located in Berlin's leading shopping and business district of Kurfürstendamm, and is ideal for business and shopping. The hotel's restaurant serves amazing food. I'd also recommend The Sofitel, in Gendarmenmarkt—Berlin's newest elite location after the unification.
Any one of the excellent restaurants scattered around Gendarmenmarkt or Friedrichstrasse are ideal for a business lunch. I'd recommend the San Nicci and Grill Royal in Friedrichstrasse. My personal favourite is Xanterner Eck, in Brandenburgische Strasse, a charming little restaurant that serves authentic Berliner cuisine.
For travelling within the inner city, automobile transit is quick and efficient. The train network is punctual and connects all the key areas.
If you have time off from work in the evenings, or a day off, you can take a sight-seeing cruise along the river Spee, or visit the Schwarzwald (Black Forest), or take a guided museum tour. There are a number of malls in Kurfürstendamm and Wilmersdorfer Strasse. KaDeWe (Kaufhaus des Westens), German for Department Store of the West, is a must-visit.
You should avoid over-indulging in beer and delicious German pastries! First timers should go to Berlin for at least 10 days to explore the city to the fullest.