Energy flows through a complex interacting network of living organisms, from primary producers such as algae and plants, to top predators such as sharks and parasites. Food webs are graphs representing these energy flows. These graphs can be viewed as couplings in a complex dynamical system that describes changes in population sizes over time. Because of the interconnected nature of living organisms, extinction of one species may have secondary effects that ripple throughout the ecosystem to varying degrees. In this talk, I will give a basic introduction to food webs, and discuss the basic network structures associated with them, as well as the methods used to generate model food webs. I will also discuss food web dynamics, and the effects of removing various types of organisms from an ecosystem network.