Actually the Tsarist government exiled Trotsky in 1900, as the Soviet Union wouldn't come into existence until 1922 and the victory of the Reds in the Russian Civil War.

For Soviets exiled to Siberia much depended on the when they were exiled. The worst period was during the dekulakization campaign in 1929/1930. The kulaks rode over-crowded trains east to find themselves in a cold, hostile environment and then had to build the camps as nothing was prepared for them. There was also a lack of sufficient materials in terms of food, clothes, and construction supplies leading many to die of starvation or the cold. The original intent of the program was for the camps to be self-sufficient and to serve as a sort of internal colonization effort, but they never achieved this and faced constant shortages of supply. The shortages came about in part due to corruption, the inefficiency of Soviet transport, and the general apathy towards the people in the camps.

Daily life involved forced labor to harvest resources in the area, usually cutting lumber. Those who were unable to meet their quota saw significant reductions in rations leading to further deaths. Families were often deported as a group in the early years of the program which further complicated life in the camps. Schooling was minimal and generally centered on political reeducation. Memorial, an organization in Russia dedicated to preserving memories of the camps, has worked with a number of historians to spread word about what happened there. A particularly heart breaking story involves a mother visiting her infant daughter in the nursery to feed it, but since her rations were low she did not have enough milk. She describes the infant crying and trying to get more before then turning away in frustration. The mother returned the next day to find the child dead.

Later iterations of the camps were less lethal, but certainly not pleasant. Alexander Solzhenitsyn chronicles life in the camps in The Gulag Archipelago and A Day in the Life of Ivan Denisovich, revealing a world of suspicion and deprivation. Assignment as a guard or overseer of the camps was generally regarded as a dead end to a career and the camp administrations were generally cruel, bitter, and devoted to extracting as much as possible from the prisoners for the administrators own gain.

Anne Applebaum's Gulag and Lynne Viola's The Unknown Gulag both offer compelling accounts of life in the camps in addition to the work of Solzhenitsyn.