Greg, if you need street signs, you'll find just about anything you need et
http://www.trafficsign.us/index.html. Just copy them to Word and resize for your scale. It's a good idea to put you scale in your signature line like I do so we don't have to guess.
If you're looking for advertising signs,
http://www.trainweb.org/tylick/signintro.htm has en extensive selection for everything from the eatly 20th century up through about the 80's. E-bay is also a good place to lood for pictures of memorabilia signs like tin soft drink and beer signs and those big old thermometer advertising signs.