I finally got around to watching this tutorial. I'm only a quarter of the way through but so far I think it's an excellent overview. My rendering knowledge is spotty and inconsistent so I expect I'll come away with a much better grounding in V-Ray.
I notice also that they've added a Twilight tutorial for those who are interested.
Some comments on lynda.com for those who haven't used this service before (I'm not in any way affiliated - just a subscriber):
lynda.com is a website that offers a very, very wide range of tutorials for many types of software. Subscription is $25/month and you can watch as many videos on as many subjects as you can cram into the month. They make it easy to unsubscribe. I think they expect you to subscribe and unsubcribe often depending on your needs.
So a strong thumbs up for this one. Well worth the $25 and after the V-Ray video I think I'll have time to brush up on some of my modo skills, take a look at the Twilight video and maybe even scan through some of the SketchUp videos to see if there's anything new to me.