Family research is like solving a mystery; you have to follow the clues!
Census reports, newspaper announcements (marriage, birth, death, etc) all help the process.
Example: While trying to find my grandfather's burial location, I called numberous Protestant cemeteries in the area looking for his resting place. I had all the information needed (date of death, name, etc.) but not the cemetery name. I re-read a marriage announcement I had found from 1880 which stated he was married by a Reverend Father Lagin. Suddenly the light went on. My grandfather was Catholic. From that clue I made two phone calls and found my grandfather and nine of his family members.
With all that information I have been able to trace my O'Brien family back to 1795 in Co Limerick, Ireland.
It can be a lot of work but does not have to cost a lot of money.
Good luck in your search.