Use these links to practice your music theory:
Lessons for review: http://www.musictheory.net/lessons
Music Theory Exercises: http://www.musictheory.net/exercises
Music Tech Teacher's awesome list of practice games: http://www.musictechteacher.com/music_quizzes/music_quizzes.htm
Sightreading practice: https://www.sightreadingfactory.com/ (Click on try it for free, then voice, then your part, then choose a difficulty level. You can practice it and then click play at the top to see if you got it correct. It will also make more for you by clicking "another one."
Major Key Signature Identification: http://www.musictheory.net/exercises/keysig/d999yyy
Major Key Signature Construction: http://teoria.com/en/exercises/ksc.php
Rhythm Dictation Practice: http://teoria.com/en/exercises/rd.php
Piano students:
Keyboard Reverse Identification: http://www.musictheory.net/exercises/keyboard-reverse/dg1g1yrybyy
Use this site with a computer keyboard to practice your music: http://virtualpiano.net/