The first advanced gravitational wave detectors are newly operational and have brought one of the most anticipated discoveries of the century: the direct detection of gravitational waves. The premier gravitational wave sources are the mergers of two compact objects. While the gravitational wave signal will give insight to the basic properties of compact objects, a coincident detection at electromagnetic wavelengths will significantly leverage the event by providing precise sky localization and an association to a galaxy. The main challenge will be how to identify the correct electromagnetic counterpart amidst an otherwise dynamic sky. In this talk, I discuss ongoing efforts to characterize the electromagnetic signatures from compact object mergers. In particular, I present observational evidence linking mergers to two distinct counterparts: short-duration gamma-ray bursts (GRBs) and long-lived transients powered by the radioactive decay of heavy elements (kilonovae). I then address how these results can help us develop observing strategies for this revolutionary era of gravitational wave discovery.