City directories provide the most direct method for learning about the people who resided in your house. Historic city directories can be accessed at many public libraries. Many have been scanned and made available online, some for free and others for a fee.
City directories of the United States of America
City directories on Cyndis List
Online Historical Directories: attempt to link to all city directories available online
City directories for major cities, at Footnote.com (subscription required, but well worth it)