Search the Message Boards for others looking for the same person(s) you're researching. You go to the Board to search but you can ask to be notified of new entries.
When you're doing census, be sure to look at 10-20 families before and after the family you are researching. These folks are the friends and neighbors (and family) of your ancestor. Families do not live alone!
There is no greater legacy for your children and grandchildren than teaching them about the history and lives of their ancestors.