Town and county histories can be invaluable to form a picture of your ancestors in the time they lived in the area..
Remember that each generation doubles the number of ancestors. It's easy to get lost if you don't plan ahead for your trip. Focus on one or two families. The others will still be there when you get to them.
Do your genealogy to learn about your family and your place in that family, to leave a legacy for your children and grandchildren, and to research and trace your family's medical history.