
Former Houghton College music professor, Ted Norton, has a great site filled lots of good stuff to help you sing better...joyfully and skillfully to the Lord.  
Heart & Voice  is happy to recommend his contribution!
Here's is the outline:
LEARNING MUSIC
        1. Music Reading for Singers - Sight Singing
        2. Memorizing Music
        3. Rhythm
SINGING BETTER
        4. How Well Do I Sing? - A Checklist
        5. Singing Better Thru Proper Breathing
        6. Singing Better Thru Register Understanding
        7. Singing Better Thru Vowel  & Consonant Understanding
        8. Intonation - Singing In Tune
        9. Learning To Harmonize
        10. Vocal Health, Warm-Ups & Singing Craft
UNDERSTANDINGS
        11. Understanding Chord Members
        12. Acoustics - The Science of Sound
EDUCATION
       13. Inaccurate Singing - Children & Adults
       14. Chapter and Quartet Management
       15. Working With Middle School Boys