Collect as much information as possible from older relatives, if possible by visiting them, otherwise by letter. Check with them as to whether anyone else has worked on the family tree and if so where can they be contacted. You may be able to save yourself a lot of time and effort by getting a copy of what has already been done. Remember growing a family tree is an ongoing task and the task is never complete. There will always be plenty of work for you to do on the history.
Verbal information is a valuable source of genealogical data.
Elderly relatives are often able to account family traditions and give eyewitness accounts of past events. Some of the information may be vague and unreliable but even garbled family traditions often contain an element of truth. You may obtain a clue to a name or date that otherwise would be located only after considerable trouble and expense. How you make contact may depend on how well you know the relative and how far away they live. By telephone or letter explain briefly what you are doing and ask for their help.