As far as I know our comprehension of brightness is logarithmic. Something with a ten-fold increase in brightness over the moon, would in reality look barely any brighter.<p>I wouldn't doubt that if the earth had a series of rings that we would still be able to see the stars. However, this would obviously depend on the composition of the rings and their albedo. Also it would vary by latitude, at the equator the rings would be barely visible.<p>Latitude would have likely been easily discernible far sooner than the usage of astronomy in navigation, it wouldn't be hard to measure the width of the rings to measure your latitude. Even a crude measurement would have been immensely useful to early ships crews. Longitude would likely have been more problematic, however knowing the moons phases and the time of day (which would be discernible by the position of Earth's shadow on the rings) would likely be enough to determine longitude.<p>I doubt human development would have been greatly affected by having planetary rings, it may even have helped the technological revolution by enabling long-distance sailing earlier.