Short answers, pulled from the story.
The Soviet decision to place nuclear missiles in Cuba was motivated by Fidel Castro's dismissal of his foreign minister Escalante and fears that Cuba would drift toward China. Historian Timothy Naftali notes this shift alarmed Moscow, prompting them to solidify the Soviet-Cuban relationship through a missile basing program.
On the 15th of October 1962, the CIA National Photographic Interpretation Center identified medium range ballistic missiles from U-2 spy plane photographs. President John F. Kennedy convened the Executive Committee of the National Security Council on the 22nd of October after receiving these images.
Major Rudolf Anderson was shot down over Banes, Cuba, by one of two Soviet-supplied S-75 Dvina surface-to-air missiles on the 27th of October 1962. The order to fire was given by Cuban military forces at the direction of Raúl Castro without authorization from Army General Issa Pliyev.
The crisis ended when Khrushchev agreed to dismantle offensive weapons in Cuba under United Nations verification in exchange for a US public declaration not to invade Cuba again. The United States secretly agreed to remove all offensive weapons it had deployed to Turkey as part of this deal.
The confrontation lasted from the 16th of October 1962 until the 28th of October 1962. The blockade was formally ended on the 20th of November 1962 after all offensive missiles and bombers had been withdrawn from Cuba.