I would venture that it really depends on your personal primary style of shooting? If you're a complete swing-through shooter, then George Digweed's video would be a good place to start.
If you're a maintained-lead shooter, Peter Blakeley's video has some very good instruction for you. Likewise, Dan Carlisle's video has gun camera footage of a good pull-away style.
There is an older video series by Roger Silcox that shows it all. In my experience, it takes the effective use of all the styles to get good at Sporting. I started with Andy Duffy's and Roger Silcox, but my video library is full and my grandson's are viewing them now.
I've viewed a lot of instructional video's from both Trap and Sporting gurus. I've taken something from all of them. Good luck in your efforts.
Thank you for your replies. I just shot sporting clays on Sunday for the third time at the Kids and Clays shoot benefitting the Ronald McDonald house. It was held at Brainerd,Nebraska and was alot of fun. The people that put this shoot together really went out of their way make everyone feel at home. I would recomend participation in this event to anyone that wanted to have a good time and support a great charity at the same time. Neil Swenson