There is a fantastic web site learning resource for Tango dancers. It is called TangoandChaos.org http://www.tangoandchaos.org/index.htm
If you start at the beginning, it reads like a book. The author is an American living in Buenos Aires.
The author is Rick McGarry of Tucson, Arizona, who spends most of his time in the USA. Someone asked me about them last night at a milonga. He married Alejandra Todaro, an Argentine, who does the lyric translations and explanations of tango culture.