The trick is finding large fish that can be caught readily. Of course, you don't have to start out with 20 pound fish. An 8 pound carp puts up a good fight, especially on light line, and is probably the largest fish caught by the majority of anglers.
The best places to start are small public waters such as the Forest Preserve Lake system in Chicago. This type of venue is easy to scout and the fish usually have no where to hide. In addition, if the water is over 10 years old, fish will have reached a good size. Public water always has carp because carp minnows are a favorite bait.
Carp are often found on the margins of a small lake or pond because that's where the food tends to be. In a public water where citizens feed the ducks, the carp are right under the food supply. Because there are few anglers interested in carp, these fish will be caught readily on bread flake or dough balls.
Another good tactic is to fish with the wind in your face. Eventually carp will migrate to the windward side of a pond because the waves cause the grubs and other protein sources to be more available.
Rivers, such as the Conneticut, the Potomac, the Red River in Canada, and the St. Lawrence Seaway, are prime producers of very large carp. CAG members report 30 pound fish on a regular basis on these rivers. Rivers are more difficult to fish, so you might want to bring a guide or an established carp angler with you. Call your district chairman for further details.