Hi Don.

You've got lots of good advice here already and possibly the only thing I can add is to be careful not to make your melody too complex. A sung melody is usually much simpler than an instrumental melody and when people write a tune on say piano or guitar, it often ends up being difficult to sing.

The rhythm of the vocal line is just as important as the notes and it's common to use what we call "nonsense lyrics" at first, just to get the number of syllables right. The nonsense lyrics are anything that comes into your head when you listen to the music and sometimes one line from these can give you an idea what the song might be about.

Composers who send music to a lyricist will often use nonsense lyrics instead of the tune played on an instrument, so the lyricist can get a better feel for how the song will be performed.

Good luck with the project!

ROG.