Amsterdam has one of the largest historic city centres in Europe, dating largely from the 17th century. At this time, a series of concentric, semi-circular canals ("grachten") were dug around the old city centre. Along the canals houses and warehouses were built. The canals still define Amsterdam's layout and appearance today. Many fine houses and mansions are situated along the canals. Some of the narrow brick houses are gradually sinking because they are built on wooden piles to cope with the marshy subsoil.
Although Amsterdam is officially designated as the capital of the Netherlands, it has never been (save a brief period between 1808 and 1810), the seat of the court, government, or parliament of the Netherlands, which are all located at The Hague. Amsterdam is also not the capital of the province in which it is located, North Holland, whose capital is located at Haarlem.

March 15th to 25th. 2012 - Roze Filmdagen Gay Film Festival - Web site
April 30th. 2012 - Queens Day - Web site
August 3rd to 5th. 2012 - Amsterdam Pride - Web site
November 2nd to 4th. 2012 - Leather Pride Weekend - Web site
Lovedance - Web site
Not a gay guide, but very informative: Web site
Held every June in Amsterdam -  Holland Festival - (Not gay) - It's a theater, music, opera, and modern dance festival.