This series of notebooks easily has the best maps around! Buy all the travel guides you want, but make sure you buy this before you leave home! Even without using the journal pages in the back, this is easily one of the best things I could buy to come to Europe. I had the Moleskine City Notebook Paris when I studied abroad and I learned very quickly to trust the maps in this book as it has every single street in the city on the map. It also has pages that list all the streets and tell you where to find them on the map!
If you're like me and you love getting yourself lost while wandering around cities, buy this book so that you can find your way back to your hotel/apartment/hostel/box at the end of the day.