Maps are not a problem on Paine. Every hiker is given a reasonable free map when you pay your Park entrance fee. (Note that the free map does not show the campsite at the west end of Lago Paine which is slowly being taken out of service. It is called Campamento Coron on older maps.)
You may want to consult online maps (they open in another window) while planning your hike:
Once in Patagonia, we recommend you pick up the widely available JLM Mapas Topographical map 1:100,000: Torres del Paine Trekking Map. It's far better than the one you get free & includes altitude charts, climbing summits, mini-maps of scenic sections, bird & animal pictures, etc.
Be careful opening it in the Patagonian wind!
There are many other maps to choose from, but almost everyone bought the JLM in 2004.
