Census records are a common source for genealogy. They can give information on where an individual was living in a certain year, who they were living with and give an approximate birth year and location. Depending on the year, it may also provide information on their occupation, whether they served in the military, where their parents were born, the number of children they have had and had many are still living, the length of time they have been married and their education level.
When trying to locate ancestors in census records, it helps to have a little information about them. Finding an ancestor named John Smith in the 1880 census would be just about impossible if that was the only thing you knew about him. There were over 26,000. However, if you added the fact he lived in Georgia, it narrows the field to just over 1,000 results. If he was in his 40s, you are down to 60.
It is a little known fact that you can use Ancestry for free to get genealogy information. They have an excellent search engine that automatically includes name variations in the results. In some years, you can hover your mouse over your ancestor's name to see more information such as household. I often use Ancestry as a jumping off point to locate my ancestors in a census, then move to Heritage Quest to view the actual census page.
Once you find your ancestor, use a census extraction form to log the information. I have links to some in my post on genealogy forms.