Researching the history of people who owned homes previously takes some time but not a lot of effort. Everything recorded against the title of a property is filed in the county clerk and recorder's office. The records contained there are public information, so anyone can search them. You'll find the names of owners recorded on warranty deeds as well as other information on liens and encumbrances--such as mortgages or trustee sale notices--filed against the property.
Gather as much information about the property as you can find including address, current owner and legal description. You'll need at least the address in order for your search to be successful.
Visit the county clerk and recorder's office. Ask an employee to help you find the files pertaining to the address you're interested in. In order to do this, the employee may have to convert the address into a legal description.
Find the correct files either by address or legal description and take note of the names on each warranty deed you find. These are the names of people who owned the property previously.
The clerk and recorder may publish its records online. But the online feature of the clerk and recorder's office may only be available through a subscription and the information may be limited to only records within the past 10 years.