German convention dictates that the house/building number follows the street name (eg Friedrichstrasse 21), and numbers sometimes run up one side of the street and back down the other side. Strasse (street) is often abbreviated to Str, and is not usually written separately but appended to the street name, as in the example above. Exceptions are when the street name is the adjectival form of a place name (eg Potsdamer Strasse) or the full name of an individual (eg Heinrich-Heine-Strasse).
Within buildings: EG means Erdgeschoss, the ground floor; 1. OG (Obergeschoss) is the first floor; VH means Vorderhaus, or the front part of the building; HH means Hinterhaus, the part of the building off the Hinterhof, the 'back courtyard'; SF is Seitenflügel, stairs that go off to the side from the Hinterhof. In big, industrial complexes, stairwells are often numbered or lettered. Treppenhaus B, or sometimes just Haus B, would indicate a particular staircase off the courtyard.