My grandma and I (ok mainly my grandma) did it back in the mid 90's by actually going to all the record keeping places, the courthouses, ohio historical society,etc. It was pretty neat. Took us about a week once we got the leads, we drove to Toldeo Ohio, Coshocton Ohio (where my family ended up settling in the early 1800's) and all the way out to some small town outside of Harrisburg PA (where my family, Hessians, settled after the revolution)
I personally recommend doing it this way as it's a lot of fun.