From a brief Google search I failed to come up with an etymology for Lenin, but I do have a theory: Lenin was born Vladimir
Ilyich Ulyanov. During his early revolutionary period, he adopted a number of noms-de-guerre, including V. Ilyin (Soviet Encyclopedic Dictionary). Maybe the nicknename "Lenin" -- which he finally adopted -- was itself constructed from "V. Ilyin".
I bet your parents were marxists to give you such a name. In Greece I have met a few folks with names such as Lenin and Stalin, all born in the late 1940s of communists parents. Marxist-chic names abound in several former communist-bloc countries, including Vladilen/a (from Lenin), Titoslav/a, Titomir/a, Staljingradka, Komsomolka (Komsa), Ruska, Vjazma, Sutjeska, Neretva, Petoletka (five year plan), and pythonesque names such as Traktor/ka (sic!) as well as a -- hold on to your hats! -- an Armenian name meaning "five year plan completed in four years." (check out http://www.ksg.harvard.edu/kokkalis/GSW2/Aleksov.PDF