Here are some useful links to do mostly with composition and choral music.
Please let me know of any others that you find useful.

Choral Connections  -  choral conductors and composers

Music Web
Composers - UK

Classical Music

Classical Search

Association of British Choral Directors

Ennerdale Music (Church music)

Pay the Piper  -  this is a nice website giving lots of advice on arranging music lessons, buying instruments, etc, etc,

Jeffery Wilson website: - composer of instrumental and choral music

Kelvedon Singers - a local choral soceity who have sung a number of Alan's pieces over the years