Dusty debris disks act as signposts for planet formation. They represent a crucial step in the process in stellar and solar-system evolution. Near- and mid-IR observations of these disks have revealed a multitude of systems with warm (>100K) dust in the terrestrial planet formation zone. Far-IR observations can reveal whether these systems also host cold belts of dust. If the cold component exists, then collisions between cometary bodies in the cold belt may be feeding the grain population of the warm dust component. If no cold component is seen, then the observed warm dust is likely the result of a recent collision between planetary embryos in the terrestrial planet zone. We present the results of a recent Herschel survey of more than a dozen known debris disks. Eight of these disks are resolved at 70 or 100 microns, and one is resolved at 160 microns. In addition to discovering the origin of the warm dust component, we can also compare the physical disk radii (measured directly from the images of resolved disks) to the blackbody radii (inferred from a blackbody fit to the dust emission). This comparison can help us to understand important grain properties.