Sight Reading Factory- Website where you can generate unlimited amount of sight reading examples (use class subscription).
Interval Website- Great Website to practice intervals.
Good-Ear.com- Online Free Ear Training Website.
MusicTheory.net- Website to practice anything music theory related.
Teoria.com- Music Theory tutorials and ear training exercises.
REC Music- Great place for song translations.
Choral Public Domain Library- You can access many different pieces that were composed at least 100 years ago here.
Sight Reading "Golden Checklist"
Bruce Phelps Sight Reading Manual Volume I- Practice Document to help you with your sight reading.
Bruce Phelps Sight Reading Manual Volume II- Practice Document to help you with your sight reading.
More Sight Reading Examples- This is another document full of practice examples.
Rhythmic Sight Reading Practice- Use this document for a variety of rhythm examples.