I wrote this post awhile ago where I recommend some books on Tsarist Russia . I also have a ton more books that I'd recommend on my profile which is here.

But to put some recommendations here

Moon, David. The Abolition of Serfdom in Russia. Serfdom is one of the core issues in 19th C Russian history and David Moon is one of the preeminent experts on Russian Serfdom, and this book is a great look at the social effects of serfdom and what happened in the wake of emancipation.

Moon, David. The Russian Peasantry, 1600-1930, the World the Peasants Made. Similar to the above book but deals with Russian peasantry before and after Tsarist Russia and even into the Soviet era.

Lincoln, Bruce W. In the Vanguard of Reform. Lincoln's book examines the role of the 'enlightened bureaucrats' who had a major influence on Russian history from 1845-1890. They helped bring about many of the reforms in this period of history and changed the way the Russian empire functioned.

I hope these help and hopefully other people can chime in on other areas!

Personally I think the books by Robert K. Massie are good both in content and a good read.

There are also various primary source books such as the Primary and Novgorod Chronicles if you want to try reading those.

And while it is not Russian there are excellent works on Poland and Ukraine which at various points had parts of their territory under imperial and/or soviet Russian control.