Begin your research with an open mind and an understanding that you will encounter many surprises and many brick walls along the way. Some stumbling blocks may include:
Surnames may be spelled differently. One ancestor might have chosen to spell his name as "Pea," while the another spelled it "Peay." Census takers often misspelled names because the subjects could not read and write. Typos, illegible handwriting and misinterpreted dialects also caused mistakes.
State and county boundaries have changed throughout our country's history. The records you need might be in a neighboring county or state. It's good to research local history to understand boundary and location name changes.
Sometimes they're simply not true. Oral history is often embellished or changes over time. Also, several people can witness an event and come away with a different understanding or memory of it. Even so, these stories provide clues that may lead you to the facts.
There are times throughout history when people moved in large numbers. (Remember, "Go west, young man!) African-Americans migrated from the South to opportunities in the northern cities. People moved for new opportunities or to escape plagues or famine. Research your family's ethnic heritage and look for clues to the whereabouts of missing ancestors.
Dates may be incorrect. In general, use the date closest to the event. For example, a birth certificate is more reliable for a birth date than a death certificate. Remember, try not to rely on one record.
You may discover that family records were destroyed by fire or flood or they were accidentally discarded. Many African-Americans may find that there are no records of their ancestors prior to 1870 because enslaved black people were listed as property and often excluded from the U.S. Census.
You may discover family facts that are not pleasant or contradict what you've been told about your lineage. Family secrets may be uncovered in your research.