The week starts with April 29th, a day that used to be celebrated as the birthday of the Emperor Shōwa, but he died in 1989. These days is it used as a day to appreciate the Shōwa Era (1926-1989), as it is called. Apparently "The official purpose of the holiday is to reflect on Japan's Showa period when the nation recovered after the turbulent times, and to think about the country's future." (from here)
The next official holiday is the 3rd of May. It is Constitution Memorial Day, the day that the present constitution came into effect in 1947.
The 4th of May is called Greenery Day or Arbour Day. This used to be the "in-between" holidays day, a non-holiday. But it finally was declared an official holiday in 2007. I've read that the Emperor and Empress attend a special ceremony on this day that includes tree planting and various presentations, sponsored primarily by the National Land Afforestation Promotion Organisation.
May 5 is Children's Day. Set aside to pray for the healthy growth and happiness of boys and girls.
The word "Golden Week" was first used by movie companies to get people to take advantage of the "golden" opportunity to go see a film. The term gradually began being used by other people to refer to this string of holidays.
Many big factories close down for a week or even 10 days because it's inefficient to keep shutting them down and starting them back up when holidays and weekends are clustered together. Although offices tend to be open on days that are not holidays, many workers use their paid vacations to take an extended break from the daily routine.
Golden Week comes at a very pleasant time of the year in Japan; temperatures are neither too cold nor too hot. Many people thus travel to resort areas. In recent years, increasing numbers have been traveling to foreign destinations with their families.
The days in Golden Week don't seem to be particularly separated into their various meanings, but rather used as an annual extended break from work for a number of people. However retail hardly seems effected. All the shops seem to be open (my gym isn't, though).
Travel on the roads around Tokyo isn't advisable at this time as they are jam-packed! Japan-Guide.com says this: "In 2013, weekends are placed in a way to create two separate holidays of three and four days. Travel activity is anticipated to peak on May 3 with people leaving the large urban centers and on May 5 and 6 in the opposite direction."
Not that it's a big deal for us at CAJ. CAJ has an interesting mixture of American, Japanese and religious holidays. But not all of any of them! As for Golden Week, we only get one of the days off, this Friday. And then on Saturday we have our middle schooler's Track Finals. We aren't going anywhere!