Think about where you want to buy land cheap. You can find cheap land in abundance in New Mexico, Arizona and West Texas if you're looking for lots of acreage. If you just want a bit of land, or are willing to pay just a bit more, the southern states have great deals on land in rural areas.
Begin keeping an eye out for buying cheap land. You'll want to stay abreast of land auctions, look at classified land ads in local small town papers, keep track of internet groups in the area you're interested in, and sign up with realtor.com. Check these sources frequently to see what comes up. You can even buy cheap land on eBay, although buying land sight unseen can be risky--see Warnings.
If you're looking for cheap land in the area where you live, one of the best ways to find it is to stay in touch with a wide range of people. You may hear about the best deals by having coffee with a few ranchers in a truck stop cafe.
Drive around the area where you'd like to buy cheap land. Keep a pen and notebook nearby, and jot down any numbers that you see on for sale signs that you pass. You never know when you'll find a deal, and many realtors will let you know of other properties that you might be interested in.
Whenever you find the land you want, do some checking before you sign any papers. Make sure that there are no back taxes owed, no building restrictions, chemical plants nearby...that sort of thing. Check out the neighbors.
Once you've decided that you want to buy the cheap land you've found, move fast. Be prepared to make a cash offer, if at all possible. If not, have a sizable percentage of down payment available. If you've really found a good deal, chances are, you'll have competition.