Rehearsal aids for choirs and choral society singers, plus midi files and sheet music for choirs:
http://www.chorusrehearsal.com/
http://nwcchorus.free.fr/index_e.htm
http://www.notation.com/MIDI-Choral.php

Choral rehearsal tapes and CDs
http://www.choralone.com/
http://www.choraline.com/

Concert listings:
http://www.concert-diary.com
Interactive Concert Guide with listings for Opera, Ballet and Classical Music Concerts across the UK
http://www.sussexconcerts.org.uk
List of concerts in Sussex

Other useful Sites:
http://www.gerontius.net
Various useful resources for choirs
http://www.musicsussex.org.uk/choirs.html
Information about sussex choirs