Sites with information about historic churches elsewhere
these sites are all recommended and many of them have links to other sites of interest

in general
Baptisteria Sacra: fonts of the world
Churchcrawler
Church Monuments Society
Corpus Vitrearum: medieval glass
Ecclesiological Society
Monumental Brass Society
The Painted Church
St Nicholas Center
Tin Tabernacles
West Gallery Churches

meet the neighbours
Cambridgeshire
Essex
Lincolnshire

further afield
Bedfordshire
Bristol
Buckinghamshire
Cheshire
Cornwall
Cornwall
Kent
Lancashire
City of London
Northamptonshire
Oxfordshire
Peterborough

Please feel free to recommend a site.