Another hint, if your family has lived for years in a town or county, try talking to other relatives, even those on the other side of the family. You will often find they are very familiar with the people in question and often have information you can use.

For a few years my wife and I have been searching for some information on her great grandfather on her mother's side of the family, I have searched every cemetery transciption I could find in that county, there wasn't even anyone buried there with the surname. We mentioned it to her dad's brother, he told me real quickly, he's buried in Cedar Grove which is two counties away. I never thought of asking Uncle Lee, he was a member of the other family, but he did know the family history.

Talk to the older relatives on both sides of the family, they often can help you with the history of the other side of the family. They may even know a few well buried secrets.