This is a Barn Spider, Araneus cavaticus, that is very common in my area of The U.S. This spider spins orb webs and watching them go about their business spinning the web is really fascinating.
In this photo she is hovering over her latest catch which you cannot see, unfortunately.
I usually find them just before sundown as they start rebuilding their webs. When they are finished they sit in the middle and wait for dinner to come to them.
A good flash and a macro lens with a high f-stop, f22 or f32, is needed to get a reasonable photo.