Not everything you want to do as an artist can be found produced by someone else. The same is true here. Often you are going to want to make some materials from scratch or alter significantly the materials you have, Dustin walks you through the generator nodes in Octane in order to help fuel your creativity.
Displacement is moving surface textures outward or inward to create mild or massive moves in the surface textures. This is a great feature for creating terrain features in planes.
Dustin has discussed using emission nodes to creating light in Octane, this whole section is dedicated to the emission node and its ability to create those lighting effects.