Former Vice President Joe Biden and Michael Carpenter, Senior Director of the Penn Biden Center and former U.S. Deputy Assistant Secretary of Defense from 2015 to 2017, have written an excellent explanation of what Russia is doing, why it's happening, and what steps we can take to defend and protect our democracy.
It's a substantial read but worth the time.
How to Stand Up to the Kremlin: Defending Democracy Against Its Enemies (Foreign Affairs)