I'm glad to hear you're exploring such an exciting period in European history, D&G, and Napoleon was a leader of extraordinary stature. But it wasn't all power and glory of course, and here's a book that fills in some everyday detail of what life was like in Napoleon's army as it headed into Russia:-
It's the real diary of a real guy who was really there: very authentic but tbh it's a slightly boring read, so if you want a quick summary," Napoleon's army was cold, disorganised and very hungry."
If you don't want to get caught up in details, you can pick up some history from Abba too
