I’ll bet one of the first bits of information you found about your Civil War ancestor is the regiment he served with. Take the time to read the history of your ancestor’s regiment. Make a special point of focusing on the regiment’s actions during his enlistment time. You can find a regimental history in the library, or check the numerous online regimental histories available.
By reading about the regiment’s actions you’ll learn a lot about your ancestors life during his military service. Not only will you become more familiar with your ancestor’s Civil War experience, battles fought, etc., you’ll have a much better sense of what resources you’ll want to pursue as you continue your research.
One place to look for a regimental history is at the Civil War Archive. Their list of histories are linked to Google books where you’ll be able to download the history in a .pdf format to your computer. This will make it easy to read and refer back to.
The National Parks Service has a regimental search page too at http://www.nps.gov/civilwar/search-regiments.htm
If you’re interested in focusing your research on your Civil War ancestor check out Ancestors In A Nation Divided – available in Kindle and also in paperback. Great help as you seek your veteran’s place in our country’s history.