I picked up the V-Ray crash course training at Flipped Normals using the Summer discount code. Even though the videos are done in Maya, it's almost a one-to-one with very few exceptions. I've literally got Modo open going through the settings as Ian (the author) goes through them in Maya. I've gotta tell you, anyone wanting to understand and get up to speed with V-Ray for Modo, this is great!
https://flippednormals.com/products/vray-crash-course/
https://flippednormals.com/products/vray-crash-course/