Write down everything your family members tell you and everything you personally remember. These are also great at family reunions, when cousins get together and at holiday celebrations. Tell family members you would like to record their memories, and try to ask them thought provoking questions. Believe me, this will save you headaches in the future. Include the name of the State a person lived in, not just the town.
Many States have towns with the same names.
Record every clue you find and save the material in an organized manner. Try to get organized from the beginning and you will be glad you did, it is terrific to be able to put your hand on a piece of information you are trying to locate. Everyone is a bit different in their method of organization, the important thing is to find a method. Many use three ring binders, I personally use a four drawer filing cabinet, with manila folders to separate types of information. You can include other information as you like as well.