For the revolution itself, Alexander Rabinowitch's Bolshevik trilogy (The Bolsheviks Come to Power: The Revolution of 1917 in Petrograd, Prelude to Revolution The Petrograd Bolsheviks and the July 1917 Uprising, and The Bolsheviks in Power: The First Year of Soviet Rule in Petrograd) are both historiographically important works on 1917 and quite accessible. The anthology Revolutionary Russia: New Approaches edited by Rex Wade is a way to get at the major historical analyses put forward by leading scholars in the field of Russian/Soviet history. If you want something a little out of left field, Time and Revolution: Marxism and the Design of Soviet Institutions by Stephen Hanson was one of the more interesting books on the Bolsheviks I've read that grapples with the fundamental question of how both Lenin and Stalin conceived of time.

For online sources, UIUC has a Russian history reading list for PhD students with a sizable section on Revolution. Peter Holquist and Benjamin Nathan also have a rather sizable list to punish their grad students foolish enough to want to take a qualifying exam in Russian history.

So, book recommendations really depend on what kind of sources youd like to read. Leon Trotsky's The Russian Revolution is quite good, and very entertaining. However Trotsky is perhaps not the most unbiased source. His books is a classic on the Revolution, and Trotsky lived through the Revolution, but it needs to be taken with a grain of salt. In that same vein, Richard Pipes' The Russian Revolution is another large and generally good book concerning the Revolution. He is a prominent Russian historian, but I have some serious problems with the way he interprets his facts and sources. Those basic facts and sources though a pretty solid. Sheila Fitzpatrick's The Russian Revolution is perhaps my favorite book on the subject. Its short, and she doesnt go into intense detail on any one event or point. Yet the book gives a decent overview of the Revolution and the Stalinist Counter-Revolution.