Another helpful site for when you have to write a musical critique. I especially like there "SHMRG" acrostic: Sound, Harmony, Melody, Rhythm and Growth (texture/formal structure) Good for students when evaluating a musical performance.
A fun way to test your music theory knowledge. The website has great videos for teaching the basics of music theory notation. The app itself is simple to use and easy to understand. As a vocalist I especially like the ear-training section.
The National Association for Music Education is a great resource for staying on to pot the latest in Music ed news. This is specifically geared to music ed professionals.