Getting the steps right is the first thing most dancers want to do. So here are a few sites where everything is nicely explained:

• a detailed explanation step by step by Flamenco Norfolk, a site that contains a lot of good material on flamenco;
• a good page about the structure of Sevillanas, but without details about the steps, by Simon el Rubio. By the way, after having surfed on this site and the previous one, you are familiar with what seems to be a passionate (at least for freaks) debate about whether or not sevillanas are flamenco dances.
• similar information, but in a format that is nice to print, by Lonnie Chu;
• if you already know what golpes, passadas and sevillanas (not the dance, but the step sequence) are, then this Canadian sevillanas dancers page might be sufficient for you;

Next comes trying it out on music. Here are some very suitable tunes:

• Relatively slow sevillana (mp3; 5.7 Mb) on guitar by Sal Bonavita. Very regular schema, easy to find out when to start dancing.;
• A sevillana (mp3; 0.7Mb) requiring more experience to dance to, performed by Grupo Adolfo de Castro from Cadiz;
• Also more complex sevillana corraleras Viva Sevilla (mp3; 0.3MB) by EL PERRO DE PATERNA.

   Thanks to Frank Naudts (Obius) and Xavier Delcour (Flash plug-in required).