Also called Golden Orb Weaver, they are known for the big web they make that is strengthened in the center with a "zipper", a zig zag weave. They get huge and they love big bugs, like grasshoppers, wasps, and sadly, even butterflies. They are harmless to humans however, altho they are scary because of their visibility--bright and big.
I read that if their web is destroyed, they will try to repair it, as it takes so much out of them to build a new one.
At the end of the season, you may find little brown "sacks" about 3/4 to 1 inch big hanging around your house. That's their babies.