If you have ancestors from the Rochester area and wish to search for articles about them, I encourage you to make use of this free resource. There are over 25 different newspapers represented.
Also I would encourage you to view this short video which demonstrates the navigation for this site. There are some interesting anomalies that you will want to be aware of.
You can search this site at Rochester, New York Region Historical Newspapers
If you are interested in other U.S. state and Canadian province collections and videos, click the links below:
Brooklyn, New York
Northern New York State
Pennsylvania Civil War Era