Remember to source (document) everything you find on your ancestors. Undocumented genealogy is mythology. Most genealogy software will get you through the basics, Elizabeth Shown Mills has authored several very good books on the subject.
[Sources & Evidence]
A census is an official counting of the population living in a given locality on a designated day set at intervals. The census places an ancestor in a specific place at a specific time.
The 1910 census lists survivors of Union or Confederate army or naval service.
Look for genealogy and history materials at scholar.google.com.
To find a birth date from a death date, subtract the age in years, months and days from the date of death. This is a very close approximation.