I'll throw in my 2cents worth. I have all of Rob Cosman's dovetailing videos and yes they are very detailed and I learned a great deal. What I would suggest is his new online school. I have learned even more on dovetails plus many other topics. You can try it for a month for less than the cost of a video. I don't think you can beat it. And no I am not affiliated with Rob in any way. Just a very happy customer.
Thanks...Bob