We discuss turbulence in the interstellar medium, specifically in cool molecular clouds and star-forming regions. Local overdensities (clouds) in these regions are known to be supersonically turbulent, with typical Mach numbers on the order of ten or more. We develop a model for turbulence in these clouds in which individual clouds dissipate their turbulent kinetic energy internally, and this internal dissipation is balanced in the mean by the injection of kinetic energy from strong shocks that arrive intermittently. Physically, these shocks correspond to the shocks from supernovae as well as other explosive events. We find that such a model nicely predicts the existence of large internal velocities with non-Gaussian statistics, as well as the observed phenomenological relationship between cloud size and line width. We also discuss star formation within the context of this model.