I don't know anything about a good video, but here is something that I think will help you. Here is a link to an on-line knitting book (free). LINK
This is the contents page. I suggest you read all of chapter 19 about horizontal seams (shoulders). Page 6 shows how to do it with ribbing, but the other pages will give you the basics, so you will know how to apply what it says about the ribbing. There are very good still pictures and text.