I have been singing professionally for 35 years, and teaching singing for over 30 years, working in many musical styles. I combine a background in professional performance, educational research, and teaching in universities, schools and the performing arts industry.
I train professional singers and singing teachers (as well as musically competent amateurs), and am very experienced in dealing with the psychological aspects of voice development and performance. Lessons include clear explanation of vocal anatomy and function (including vocal acoustics), how to alter the vocal set up for different styles (e.g. opera, music theatre, folk, rock, choral singing etc), and what is healthy for the voice.
On my website - http://www.OxfordSingingLessons.co.uk - you'll find some ideas to get you started straight away on improving your singing voice (free resources, videos, articles and links).
In addition, I am a published songwriter, and I teach songwriting (both music and lyrics) at http://www.OxfordSongwriting.com.