Music Note Name Flash Cards
Click the 1st or 2nd selection of the left column - on the next page click Play to practice.
http://www.netrover.com/~kingskid/note_naming/flash_card/flash_cards.htm

Playmusic (site on musical instruments)
http://www.playmusic.org

Llerrah Music
http://www.llerrah.com/jukekids.htm

Baroque Music
http://essentialsofmusic.com
http://www.jsbach.org