Anything including daily life of denizens and the ruling class, government structure, military strategy, foreign policy, and economics interest me. I am looking for some good sources preferably print.
I would recommend:
Bismarck and the German Empire by Erich Eyck and
The Second Reich: Germany, 1871-1918 by William Simpson
They are both very informative and surprisingly interesting.
Roger Chickering is in large part an authority in the English-speaking world on Imperial Germany and the Great War. See Chickering's short Cambridge volume, Imperial Germany and the Great War, 1918-1918 (Cambridge University Press, 1998) and his much larger book on Freiburg's experience during this period, The Great War and Urban Life in Germany: Freiburg, 1914-1918 (2008). The latter study is extremely comprehensive and answers many questions about life in Germany during the war. He uses variegated and rich archival sources. I highly recommend it.