The Soviet efforts regarding the moon were centered around the Luna series (1957-1976) comprised of twenty-four total missions which were characterized as dramatic successes or failures. Although the primary effort behind these missions was to lay the foundation for a future manned mission, something that would never eventually materialize, the various Luna probes accomplished a wide variety of achievements (and "firsts") including the imaging of the far side of the moon (Luna 3), lunar impact crashes (Luna 2, 5, 7, 8 and 18), lunar flybys (Luna 1, 3 and 4), lunar soft landings (Luna 16, 17, 21, 23 and 24), lunar orbitters (Luna 10, 11, 12, 14, 15, 19 and 22) as well as unmanned missions which included samples of lunar material returned to earth (Luna 16, 20 and 24). Further amazing details regarding each of these missions are available here.

Note: Although less-well known, the Soviet ZOND project was also a successful undertaking to the moon covering five missions between 1966 and 1970. For additional details, click here.