Online training for shaders/material understanding for beginner

[stevesideas]

Hi. Would anyone recommend a course for a Vray CGI beginner that needs to push his shader understanding to a more professional level. I feel Grant Warrick's courses are too advanced for this person right now so ideally it would be something that just pushes his understanding of using various Vray shaders together with masks and Vrayblend etc.

Any advice appreciated. Cheers