Let me see if I can help you out with a few tips. The first thing I would do is to make a paper map of the main house and any out buildings, or at least out building foundations. A house that old should have had an outhouse, most likely in the rear of the main dwelling or on the predominately downwind side. You should also find the remnants of a chicken coup. All families in the country in the 1800s had some type of building for keeping chickens. Most families had some type of barn or lean-to for keeping livestock. If they had only a horse for transportation, they would have a small lean-to, if they had several livestock they would have something more resembling a barn. Next you should look for the remnants of a clothesline. Take note of any trees close to the house that you can't wrap your arms around and touch your fingers on the other side. These will be trees that were most likely there originally. Also, as Shrecky mentioned, look for a tree line or fence line depicting the outside of the main yard. Another thing you will want to find out is if there was a well there. Some folks had sisterns and some had wells. Knowing where these things are will help you concentrate on the most likely area for targets. There is always the chance of finding a cache around a home like this. I would personally run in all metal mode and determine what to dig by the size of the signal. A small iron target like a nail would not be dug, but a large iron target could be a good relic. You could find horse shoes, Ox shoes, old lanterns, the list is endless. A large iron target could also be a cache of coins or jewelry. Many folks used tin cups or boxes along with mason jars to bury the family savings. If you are limited on time to detect this property due to future construction or development, you might try to cherry pick for old silver, if you have some time, like a whole summer, I would take my approach and really get the most from it. If possible, you can get on one of the Terra server websites and get an overhead view to help find the remnants of outbuildings. Research really pays off if you have the time.
Hope these suggestions help you. Would love to see some more pics of the place. Good luck on your new adventure into finding history. Happy hunting.