IMSLP - Petrucci Music Library - This contains free public domain music of all types of instruments and arrangements from solos to whole orchestral pieces. This is a great place to search for older pieces of music.
The Mutopia Project - This is another free public domain site of sheet music predominantly classical music.
Music Scores - There are many free scores of music here that I have enjoyed using, plus other arrangements which may be purchased.
Metronome Online keeps track of the time you practice with a metronome and allows you to enter practice goals.
Metronome Bot - Another free online metronome with cute robots helping to keep the beat. Different sounds and meters are available. "Rhythm in Music" has interactive rhythm lessons to help improve your rhythms.
Impro-Visor - I have not tried this one yet, but it looks like a fun tool for students who want to learn more about jazz.
Scale / Fingering Printouts - This resource from Yamaha has instrument care info, fingering charts, major and minor scales, and tone exercises to print out for all band instruments.
Sight Reading Factory - Sight reading is an important skill for musicians of every level and instrument. This web site allows you to click on your instrument, level, and time signature and it creates a new sight reading piece for you to play instantly. Great idea to do this frequently to improve skills!
Hyper Physics - This musician find science cool especially when it is related to music! Check out the Physics of several instruments. Info here would make a cool science fair project or report!
Woodwind Intonation - need help playing your woodwind in tune? Read about several reasons why it is hard and find tips to play better in tune.
ABRSM Resources - Find "Woodwind Practice Partners" that play accompaniment for you to practice with; use the "Speedshifter" App to slow down a piece but keep the same pitch (all instruments); increase your listening skills with the Aural Trainer App; or improve your scales with the Scale Trainer App.
If you need sheet music, Sheet Music Plus has an awesome variety. Let me know if you need help finding something.
Music Theory Lessons - several levels of Music Theory Lessons may be found here for free or you may download one of their apps for devices.
Music Theory Exercises - This correlates with the above site but has practice exercises on note reading, scales, chords, key signatures, and ear training.
Flute Tunes - This is one of my favorite sites not only for flute students, but for everyone! You will find an online metronome and tuner (required of all my students), flute fingerings, scales pages to print out (great for all instruments), and tons of free sheet music to use for sight reading and playing.
Jennifer Cluff - Ms. Cluff has many articles, activities, and exercises to help flute players.
Flutes - You can find links to just about everything flute here!
Clarinet Scales / Fingerings - Click on the printable scales chart to find and print clarinet scales. Click on the sidebar to find clarinet fingerings and other clarinet information.
Clarinet Fingering Trainer - A fun way to practice clarinet fingerings. When the trainer gives you a note, click on the keys and submit the correct fingerings. It will keep score for you and let you know ones you do not know.
Clarinet Info - Scroll down to find clarinet charts, exercise, and advice.
The Clarinet Institute has an insane amount of free public domain music for clarinet solos and chamber ensembles!
The Clarinets - an interesting site about the history of the clarinet and more.
Piano Please see the "Printables" page for links to flashcards, worksheets, scale and chords pages, and lead sheets.
Piano Triads & Chords - click on the chord you want and it will show you what it looks like on the keyboard and staff. This would be great if you find a new chord on a lead sheet and want to know what notes belong in the chord.
String Education - look under the Teacher Toolbox for some note reading - fingering flashcards, worksheets, and printable scales sheets.
Percussion 101 - find videos on proper playing techniques of common percussion instruments.
Theta Music Training Games - Find great music theory games here. Some are totally free, all games allow you to play the first three levels free, too. Have fun!
The Rhythm Trainer - Select rhythm patterns that the computer will use to create a 4 beat pattern that you have to build to match! How many can you get in a row?
Music Racer - 3 games here that you can customize for your instrument: note reading, fingerings, and music terms! How fast can you name them all!
Name the Pitch Game - This may be used for any instrument player who wants to improve their note reading. There are many different levels in both treble and bass clefs.
Music Tech Teacher has many fun games related to music theory, note reading, rhythms, and more! Have fun learning!