The national headquarters of Girl Scout of the USA is located on Fifth Avenue in New York, NY.
The headquarters/World Bureau for the World Association of Girl Guides and Girl Scouts is in London, England.
The web address of the Girl Scout First Headquarters Building is: www.girlscouting.org
The address of the Girl Scout First Headquarters Building is: 330 Drayton St., Savannah, GA 31401
Girl Scouts first started selling cookies in 1917 as a way to finance troop activities, so you could say that the girls themselves "invented" Girl Scout cookies! In 1922, an article was published in "The American Girl" magazine, published by the Girl Scout national headquarters, about Girl Scout cookie sales, including a recipe and suggestions for cookie prices. The article was written by Florence E. Neil, a local director in Chicago, Illinois.
This answer depends on what you mean by "centers". There are no Girl Guide/Girl Scout World Centers located in the US. Girl Scouts of the USA has the Edith Macy Conference Center, the Girl Scout National Historic Preservation Center, and the Juliette Gordon Low Birthplace A National Center of Girl Scouts of the USA. So there are 3 national Girl Scout centers. There are more than 100 GSUSA Councils and each of them has at least one office and possibly other places they call 'centers' so a definite number would be difficult to determine.
I went to Savannah, Georgia, the girl scout headquarters. or I am in my super, secret, spy, headquarters. Due to your manners you may decide which is more fit to use for your purpose.
The Asociación De Guías Scouts Dominicanas Inc. national headquarters are located in Santiago and there are companies and packs in all provinces.
New York City
In Colombo, Sri Lanka
The Chief Commissioner of The Girl Guides Association of Grenada is located in St. George.
Since each Girl Scout council controls their cookie sale, and there are two different cookie companies, this may be difficult to determine. In my experience, 100 boxes was the average for our area.
The highest award a Girl Scout member of Girl Scouts of the USA can earn is the Girl Scout Gold Award. The Girl Scout must be a Girl Scout Senior or Girl Scout Ambassador in order to work on the 7 steps required to earn the Girl Scout Gold Award.
Each Girl Scout Council has their own store, usually located at the main Service Center. There also is an online GSUSA shop - see related links for a link to the GSUSA Shop and/or to locate a Girl Scout shop close to your location.