A book I really like is The Soviet Experiment by Ronald Suny. He takes a lot of time to give the historical lay of the land which is nice because then you get to see what other historians have said, giving you a bigger picture. It's also pretty exhaustive and has a massive bibliography section to give you more suggestions on what to read.

A very interesting book about the October Revolution (the Bolsheviks taking power in 1917) is Ten Days that Shook the World by John Reed. He was an American journalist who was in Petersburg during the short time where the Bolsheviks overthrew the Provisional Government.

To go along with what /u/WalrusWarlord said, the final years of the fall of the Soviet Union is covered in meticulous detail by Serhii Plokhii in The Last Empire: the Final Days of the Soviet Union