Oof, this is my area of focus. How deep are you interested in going, are you interested in particular people or aspects of pre-Revolution/Civil War/Soviet life? In terms of things that I think non-Russian-dorks would like, that give a view of the culture, I really can't recommend Simon Sebag Montefiore's biographies of young and adult Stalin enough. Really written in a way that gripped me even though my interest has always been much more pre-Revolution than USSR.

Orlando Figes has written a number of good books as well, ranging from a cultural history of Russia to books specific to the Stalin period. W. Bruce Lincoln's books tend to be geared more towards the period that you're talking about, particularly books like In War's Dark Shadow that focus pretty intently on the period surrounding the 1905 and 1917 upheavals. Just about all his books that I can think of would fit the time period you're after.

I'm unfortunately not at home to stare at my library, but hopefully that'll give you a start! Russia in that fifty years is incredibly interesting.