The presence of a crosswalk generally gives pedestrians the right of way. At traffic lights, there are normally the usual car traffic lights (red, yellow and green), and then "pedestrian traffic lights" that face the crosswalks. The pedestrian traffic lights usually light up white in the shape of a person when you have the right of way to cross the crosswalk, or they show a red hand if you do not have the right of way.
For crosswalks not at an intersection (typically when there is several hundred feet of road without an intersection for crosswalks), I believe pedestrians always have the right of way. Sometimes they have a button you can push that will activate yellow lights overhead so drivers know that you're crossing (primarily useful at night). I think you have the right of way regardless, but given how little attention many people pay, I tend to treat them like I'm jaywalking anyways.
For crosswalks not at an intersection (typically when there is several hundred feet of road without an intersection for crosswalks), I believe pedestrians always have the right of way. Sometimes they have a button you can push that will activate yellow lights overhead so drivers know that you're crossing (primarily useful at night). I think you have the right of way regardless, but given how little attention many people pay, I tend to treat them like I'm jaywalking anyways.