Short answers, pulled from the story.
The New Union Treaty was a draft treaty intended to replace the 1922 Treaty on the Creation of the USSR and reform the Soviet Union into a confederation of sovereign and equal states. Mikhail Gorbachev proposed a less centralized federal system at the Communist Party Congress of July 1990 to prevent the union from fragmenting.
The Novo-Ogaryovo process was the series of negotiations carried out at Novo-Ogaryovo, a governmental estate, where Gorbachev met with leaders of the union republics to draft the treaty. The 9+1 agreement between the Soviet central government and nine republics was signed there on the 23rd of April 1991.
Six republics did not participate: Armenia, Georgia, Moldova, Estonia, Latvia, and Lithuania. All six were already moving toward independence and their citizens largely boycotted the March 1991 referendum.
On the 17th of March 1991-76 percent of voters in the nine participating republics supported maintaining the federal system of the Soviet Union. A majority voted in favor in all nine republics, though opposition was highest in large cities such as Leningrad and Moscow.
The signing was scheduled for the 20th of August 1991 but was prevented by the August Coup. On the 18th of August, hardliners confined Gorbachev in his Crimean dacha to stop him from returning to Moscow to sign the document.
The Belovezha Accords, signed on the 8th of December 1991 by Russia, Ukraine, and Belarus, formally dissolved the Soviet Union. The Commonwealth of Independent States, an organization of twelve newly independent states, was created to replace it.