An Illustrated Compendium contains a database of all the dances from all the editions of John Playford's Dancing Master . There are quite a few websites and newsgroups devoted to specific musical instruments. The Roots.net collection of instrument links has disappeared again. Although not exclusively English in scope, the following resources certainly include English folk music and contain links to further resources. Although there are dozens of fiddle and guitar sites, I have only found a couple which are particularly relevant to players of English music.
Further recommendations welcome.
There are a few instrument makers listed on my folk music businesses page. The Usenet newsgroup rec.music.makers.sqeezebox Bagpipes Julia Say's Northumbrian small pipes encyclopaedia - perhaps the only instrument used solely for playing English music. The Usenet newsgroup rec. Elaine Bradtke's Fiddle Notes Chris Bartram 's site contains a lot of interesting material on the fiddle in traditional music in southern England. The UK academic discussion list Ballads at JISCmail.