From what my dad in law taught me is to drive around and see what I like if it is for sale. Also get lists from various realestate agents. Then drive around and see what you like and when you find something then get the agent to show you it. That is what he does.
Cheryl

First decide what you want to do with the land. That will determine price in many areas. Rocky, unfarmable land is cheaper than good farmland. Wooded property is cheaper than cleared land, but you have to take into account the costs to clear. Consider access. Are you willing to be 50-100 miles from a grocery store? Easy access to utilities will cost more than property that is off the beaten path and electricity isn't readily available, but it may cost thousands of dollars and months to bring in the electricity. Will you be raising things to sell? How close is your market? How big of a property will you need? Larger tracts are generally cheaper by the acre. What kind of climate are you willing to live with? I can't handle cold, but I have gotten used to heat. No way I could live with the long cold winters in Montana. If you are growing things to sell, what is the growing season you will need?

Once you have a beter idea of your needs, contact a local real estate agent. They can make contact with agents in other parts of the country and even give you internet sites to go search yourself. In the Houston Texas area, we have har.com, which covers about a 12 county area all around Houston, and about 100 miles out. Other areas of the country may have similar sites.

I know I am pretty late on this one...but try LandAndFarm.com It is an awesome place to visit if you are in the market from woods / cropland / farms already set up & just about everything in-between. If I hadn't already built my dream home in SW Ohio, I would have looked into about 100 of the places on this website. Good Luck!