Without having pre-read the book, I'm putting together a list of potentially helpful links, albeit slightly ignorantly. Maybe if you've used/read the book, you can be of some help in indicating which of these might be the most helpful. This post will hopefully change as we go along. I'll toss the unhelpful things and perhaps add more along the way :)
So, without further ado...
The actual map we will hopefully be able to use the most alongside the reading. Links to other maps to print and use for drill (including blank) here.
Wiki entry on the Grand Duchy of Moscow (1340-1547) and Tsardom of Russia (1547-1721).
A cool looking map here.
Maps showing progression/expansion of the Grand Duchy of Muscovy. Click the years on the left sidebar to see changes.
Cool old looking illustrated map (pictured above).
Online bio of Ivan the Terrible.
Site for general info about Russia (including historical and modern facts).
Some helpful wikis: Tsardom of Russia and Anthony Jenkinson (Muscovy Trading Co., 1529-1610)