I started to post this under salsa, but it really does fit a broader category than that. This guy, Don Baarns, is a musician/music teacher who has a very cool series of videos on youtube and a nice blog (all free of charge) that break down music and culture of social dance. Lots of information!!
I bought his ebook, but haven't read it yet,so I can't comment on its quality.
But ... he's definitely worth checking out,IMHO. Heck. Subscribe to his youtube channel. It's free.http://www.unlikelysalsero.com/https://www.facebook.com/UnlikelySalsero
Here's an example of one of his educational videos:http://www.youtube.com/watch?v=l4WhdmqsNP8