CWhunter, that is a good question! That might depend on the owner and the circumstances, I guess. Since I am new to this also, I am learning as I go along and would love to hear what others have to say on this issue.
I think if I found a lot of interesting/valuable stuff, I'd tell the owner. Also, he was outside in his vegetable garden yesterday when I was searching, so he noticed some of what I found. He was interested but didn't want anything except I found a socket that he had lost and was looking for because it was part of a set, LOL, so he was happy to have that.
So far I've found some interesting things but no silver or high value items. Kind of odd stuff, really. I only had about 2 hours yesterday and then it started raining. Spent part of that time speaking with the owner as he wanted to tell me where he had found interesting things on the property, such as that there was a bottle/trash dump across the road from the original house in the front of a field. And that there were often arrowheads found in the back of his wooded area near a creek. He also told me where there used to be some other old buildings on his property and some nearby properties in the neighborhood.
I plan to spend many days on this property as there is a lot of area to search. Some places are pretty trashy but I think clearing it out will be worthwhile. I was working along a stone wall that edges what would have been the stableyard/paddock in front of the barn and on the backside of that wall folks had randomly heaped more stones over the years. I was getting hits all over the place under the small stones. Further investigation turned up old broken glass and a lot of things that look like they might be old milk bottlecaps or something. It looked like someone was dumping trash as well as stones in that area. The owner said I could move any stones I wanted, just to put them back. It started to really pour rain while I was still looking for whatever was ringing silver in/under those stones. I will be returning as soon as I can. I think it could be worthwhile to search all along that rubble at the edges of that wall.
I found a piece of costume jewelry that was a charm bracelet with, of all things, a charm shaped like a city bus, under a tree on the side of the front yard. Some clad. Lots of trash of course, including some old tractor parts (at least, that's what the farmer thought they were).
Gator01, both houses are still standing. The 1823 stone house is being used as a wood shop (it is very small) and the larger stone house is where the owner is living. The barn is very old as well.
Once I'm done with the wall, I'm going to hit all around the original home to see what can be found.
What does everyone think about the various trash heaps? There is the old one across the street where the owner found bottles, and there is an area in the back where they drag trash to burn and it looks like stuff might have been dumped years ago.
Thanks again to everyone for all of your advice. I don't have a smaller coil yet, but where I was getting multiple hits I was just using my pro pointer and it was going a good job of finding the multiple targets.