The United States Geological Survey has made their collection of old paper topographic maps available to download for free as PDFs through their Map Locator. Simply search for a ZIP Code or place name (but don't search a street address) and a map will appear showing the boundaries of USGS quads. From there, you can download PDF maps.
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Digital Data Services offers a great utility called MapFinder that is very user friendly in locating these USGS Topo Maps.
http://www.usgsquads.com/index.php/map-indexes/mapfinder
Also, as a GIS Firm they offer related services including having the capability to print and scan large formats.