Lenin wrote the text that became the April Theses while he was in exile in Switzerland; they were published when he returned to Russia in April, 1917. In February of that year, Tsar Nicholas II had been deposed and a provisional government had been established. Lenin returned to Russia as quickly as possible after the ouster of the Tsar; his April Theses were his statements of conflict with the provisional government and his proposals for a new governing order in Russia.
The Theses proposed:
-that the provisional government was a puppet of the bourgeois upper class and needed to be overthrown
-that the ultimate governmental model needed in Russia was "a republic of Soviets of Workers', Agricultural Labourers' and Peasants' Deputies throughout the country, from top to bottom."
-that all privately-owned farmland (the vast estates of the bourgeois) needed to be nationalized, followed by the establishment of large communal farms governed by the peasant farmers who worked them
-that the proper name for the new political party being formed by the Bolsheviks should be the Communist Party in recognition of the communist philosophy and organization being advocated