When on the road, I'm always looking for interesting photographic opportunities.
Along with POIs & websites, I always visit with campground hosts to ask about what is in the area. Where else, for example, would you find that there is a
concrete canoe race going on in the local lake that afternoon?
Another great source, at least in small towns, is to ask at a visitor center. While many centers are just there to lure you into hotels & typical tourist attractions, the volunteers at the small ones will know a great deal about the area & will be willing to listen to what you are looking for & provide valuable info.