Berlin

History
The area of Berlin was settled first by Slavic tribes in the 700’s. Berlin received city rights in 1242. In 1701 Berlin was the capital of Prussia. The Swedes occupied Berlin from 1618-1648, the French in 1806, and the Russians in 1945. The siege of Berlin in WWII wrecked 70% of the city. After WWII the capital of West Germany was moved to Bonn in 1949. The capital of East Germany remained Berlin. The Berlin Wall, built in 1961, was crossed on November 9, 1989. German reunification, which many of us thought would never come in our lifetime, came on October 3rd, 1990. In June 1991, the German Parliament voted to move the German capital from Bonn back to Berlin. Government Offices moved back from 1997 to 1998:

E-Mail Lists
http://lists.rootsweb.com/index/intl/DEU/DEU-BERLIN.html
http://feefhs.org/DE/BER/BERLINRL/BERLINRL.HTML  Message Board
http://archiver.rootsweb.com/th/index/Berlin Message Board

Maps
http://en.wikipedia.org/wiki/Image:Berlin.bezirke.png showing the districts of Berlin 
http://www.alt-berlin.info/pages/index.htm 1738 to 1999
http://mitglied.lycos.de/Pomerania2/images/Baed4.jpg Detailed 1809 map
http://www.geocities.com/CollegePark/Field/5675/ 1938 map, click on the square you want 

Archives and Records
http://www.genealogienetz.de/reg/BRG/bb.html

Many records exist for "Do a Place Search" here:
http://www.familysearch.org/Eng/Library/FHLC/frameset_fhlc.asp

Books
The GGS collection of Germanic Genealogy Books at Concordia University in St. Paul, MN has 7 books specifically on Berlin genealogy, of those 7 books 4 are in German. 

Flags
http://en.wikipedia.org/wiki/File:Flag_of_Berlin.svg
http://images.google.com/images?hl=en&q=berlin+flags&um=1&ie=UTF-8&ei=Vl-zS9eNM4yENpbQ5ewD&sa=X&oi=image_result_group&ct=title&resnum=4&ved=0CB4QsAQwAw