I'm with SDS-GEN on this one. In any county with significant agriculture, the USDA will fly aerial photography every summer. They can print out a copy of the tract you'll be hunting. For the past few years, they've used digital photography. Depending on the office, you might be able to get a digital copy. I use these at work all the time. In our area, USDA photography has 2 meter resolution. It would take me forever to download that kind of detail over a modem.
If you're in a part of the country that's largely forested, they might not fly your area. Here in Missouri, they generally don't fly all the southern counties since there's darn little cropping going on in parts of the Ozarks. Go with TerraServer or Google Earth if that doesn't work.