We provide a review of our recent work on the development of a multi-scale simulation methodology to calculate the rheology and flow of wormlike micelles. There is a great need for understanding the link between the detailed chemistry of surfactants, forming wormlike micelles, and their macroscopic rheological properties. We show how this link may be explored through particle simulations. First, we calculate the mechanical properties of small units of wormlike micelles from atomistic molecular dynamics simulations. These mechanical properties are subsequently used in a coarse-grained Brownian dynamics model, where the persistence length is the smallest length scale. We show that the non-Newtonian rheology of wormlike micellar systems can be accurately determined from our simple mesoscopic simulation model. Finally, we show that this mesoscopic model can be used to study the flow of wormlike micelles in contraction-expansion geometries.