Dance:
Folk Dance New Zealand – NZ folk dance directory
The Society for International Folk Dancing – UK-based International folk dance promotion organisation (akin to FDNZ in New Zealand)
Society of Folk Dance Historians – informative site covering an extensive list of folk dances
Folk Dance Federation of California – extensive archive of dance notes, etc
Ruritanian International Folkdance Club – Auckland-based folk dance information, diary, etc
Costumes, audio, songs, instruments, etc:
Balkanfolk.com – company in Sofia/Bulgaria selling folk costumes, music, instruments etc. from the Balkans
MIT Songbook – a huge collection, by MIT, of folk song lyrics (with English translations) from around the world
Macedonian Folk Songs – an immense collection of Macedonian songs
Folklore Songbook – large collection of songs for folk dances (site in German, but easily navigated)
Eliznik Romania – lots of information about Romanian dance and ethnography, including costumes
Musica Balkanica – Christchurch-based choir specialising in music from the Balkans, folk & sacred