Digital Tutors has a huge collection on rendering tutorials (96 it says) for Cinema4D users. These tutorials range from beginner to advanced. Check them out HERE. Courses include a free introduction to rendering in Cinema4D, Rendering for Product Visualization in CINEMA 4D, Creating caustic light patterns in CINEMA 4D, Creating Shadow Caster lights within CINEMA 4D, and Using subsurface scattering in CINEMA 4D.