Elevated and well drained soils area near a good source of water is a good place to start. You guys that have access to the banks of the Ohio River will probably have the best luck in finding artifacts. There are many places where the river is eating inton the bank and exposing more artifacts every spring. Lots of trespassing going on as the result. Remember that it is against a State law to do anything more than just a surface reconnaissance without a permit even on your own property. To get such a permit, you have to be a qualified archaeologist who is on the list of qualified archaeologists maintained by the IDNR, Division of Historic Preservation and Archaeology. You also need to submit a plan and justification for what you want to do. This law was our legislature's knew jerk reaction to something that happened down in Posey County many years ago. So, if you are out digging for artifacts and are questioned by a conservation officer, just tell him that you are digging for night crawlers. If you tell him what you are actually doing, he might cuff you and haul you off to jail. If you want to know what can happen to you for trespassing and illegally looking for artifacts, just look up a guy named Jack Gerber from Tell City, if he is still alive, and he can fill you in.
I used to live in a house that was built in 1902, and I metal detected a shoe box full of the old cut nails they used when building the house. In some spots the nails had rusted into globs of iron, and in one place, they looked perfectly fine.i found a 1930's wheat head penny that washed up in some disturbed dirt in my yard
i havent metal detected the new yard yet but im expecting to find some neat things.