Common British, Canadian, South African, and ANZAC traditions include two minutes of silence at the eleventh hour of the eleventh day of the eleventh month because that was the time (in Britain) when the armistice became effective.

The Service of Remembrance in many Commonwealth of Nations countries generally includes the playing of the Last Post, followed by two minutes of silence, followed by the playing of Reveille (or, more commonly, The Rouse) and a recitation of the Ode of Remembrance. The Scottish Bagpiper's Lament is often played during the Service. Services also include wreaths laid to honour the fallen, a blessing, and National Anthems.

United States

Veterans Day is commemorated in the United States on 11 November, and is both a federal holiday and a state holiday in all states. However, the function of the observance elsewhere is more closely matched by Memorial Day in May. In the United States, and some other allied nations, 11 November was formerly known as Armistice Day; in the United States it was given its new name after the end of World War II. Most schools, particulary more middle and high schools than some elementary schools, throughout the U.S. usually hold assemblies on a school day prior, with various presentations recognizing teachers and staff members who served in one of the five branches of the United States Armed Forces, as well as remembering the U.S. troops who died in past and present wars, and some patriotic music by a school choir, band and/or orchestra, including songs from a musical used as a tribute to the troops (e.g. "Bring Him Home" from Les Misérables).

http://en.wikipedia.org/wiki/Veterans_Day

The poppy's significance to Remembrance Day is a result of Canadian military physician John McCrae's poem In Flanders Fields. The poppy emblem was chosen because of the poppies that bloomed across some of the worst battlefields of Flanders in World War I, their red colour an appropriate symbol for the bloodshed of trench warfare. A Frenchwoman, Anna E. Guérin, introduced the widely used artificial poppies given out today. Some people choose to wear white poppies, which emphasises a desire for peaceful alternatives to military action.

The inspiration for the verses had been the death of a fellow officer, Lt Alexis Helmer, of the 1st Brigade Canadian Field Artillery on 2 May 1915, during the Second Battle of Ypres (Ieper) in western Belgium, for whom McCrae had performed the burial service. McCrae's verses, which he had scribbled in pencil on a page torn from his despatch book, were sent anonymously by a fellow officer to the English magazine, Punch, which published them under the title 'In Flanders Fields' on 8 December 1915.

Origins of the Memorial Poppy

The idea for the Flanders Fields Memorial Poppy, Moina Michael recalled in her 1941 book The Miracle Flower, came to her while working at the YMCA Overseas War Secretaries' Headquarters on a Saturday morning, 9 November 1918. The Twenty-Fifth Conference of the Overseas YMCA War Secretaries was in progress. During a lull in proceedings Moina glanced through a copy of the November Ladies Home Journal and came across McCrae's poem re-titled "We Shall Not Sleep". The last few lines transfixed her:

To you from failing hands we throw
The torch; be yours to hold it high.
If ye break faith with us who die
We shall not sleep, though poppies grow
In Flanders fields.

Moina Michael hereafter made a personal pledge to 'keep the faith' and vowed always to wear a red poppy of Flanders Fields as a symbol of remembrance. Compelled to make a note of this pledge she hastily scribbled her response, entitled "We Shall Keep the Faith", on the back of a used envelope.

When the Conference delegates gave Moina a gift of ten dollars in appreciation of her assistance, she went to a New York department store and purchased 25 artificial red poppies and, pinning one on her own collar, distributed the remainder to the YMCA secretaries with an explanation of her motivation. She viewed this act as the first group distribution of the Flanders Fields Memorial Poppy.

Moina Michael hereafter tirelessly campaigned to get the poppy adopted as a national symbol of remembrance. In September 1920 the American Legion adopted the Poppy as such at its annual Convention. Attending that Convention was a French woman who was about to promote the poppy — as a symbol of remembrance — throughout the world.