Music Teachers Online Find a teacher in your area.
Blitzbooks AMEB theory and musicianship books. Great for kids! Written by the Australian, Samantha Coates.
Theta Music Trainer Online Ear Training. Train your ear with fun music games.
Teoria José Rodríguez Alvira. Excellent theory site including exercises. Interactive Quizzes, Crosswords and Mazes - on everything from the Basic Elements of Music Theory to Analysis of Late-19th century music and Post-Tonal Theory
SolFi Ear Trainer Pro (for iPhone, iPod touch and iPad) ear training software
Stars & Catz Music Teacher Network Stars and Catz is a large community of private music teachers and music schools backed by a team of people who are focused on matching students to the right teacher based on their needs. See website for full details.