There is great resources on the subject, including some on our Book List.

Orlando Figes' A People's Tragedy goes into detail the extent of Lenin's influence on events and the ultimate "tragedy" of the revolution.

Sheila Fitzpatrick's Russian Revolution would also be a good choice.

The elephant in the room is Robert Service's Lenin: A Biography. It was one of the first of its kind and it does an amazing way to show who Lenin was, and what he did.

Stay away from Richard Pipe's book on the revolution which has been largely discredited.

Finally, Trotsky wrote some memoirs on the revolution, but also Lenin, and would be good primary source material.

Edit: He also petted many cats during his tenure.