New Plastic quickly covers all the Octane nodes and their purpose.
New Plastic has a new video series that runs through all of the Octane Nodes there ever was and their purpose. The series is a deep dive into how the nodes work, but this tutorial is for you if you are confused about what does which.
New Plastic’s Fabrics Pack for Cinema 4D (Procedural Octane Pack)
New Plastic offers a few shader packs, and the Fabrics one is pretty good! The Fabrics Pack for Octane includes 159 pre-made fabric materials. Get that here.