http://persi.heritagequestonline.com/hqoweb/library/do/census/search/basic
I can access this database with my library card and your library may have the same access too. Mine is through Galileo. The only problem I saw was they don't have all the census records for example William Austin Leyden did not appear in Georgia and he lived there since its inception in 1847. It also did not list some of my relatives who I know were there but the census records available are very detailed. If you find your ancestor in the census there is a lot of information available.
I have to brag on the book section. You can search by people, place and publication. i searched Cassville and found a copy of the History of Bartow County formerly Cass by Lucy Cunyus, scanned online. I also found books like
The Seventy-seventh Pennsylvania at Shiloh Harrisburg, Pa. :: Harrisburg Pub. Co.,, 1905, 447 pgs.
If you are searching for something just ask and I will search for you.