Clickable map of Mexico that shows states and cities
Regional association: Jalisco
A brief essay on mariachi by Daniel Sheehy.
Lyrics to many Mariachi songs may be found here: http://www.elmariachi.com/
A very international, inter-ethnic and, by the way, all female maricahi: Mariachi Divas ; their website has several interesting artist bios.
The Smithsonian Institution’s website on corridos is excellent: http://www.corridos.org/
Some notes with sound examples on Norteña, Trova Yucateca, and the marimba in Latin America