I have found the following links to be useful in Genealogical research. The list is sorted in order to group like sites together.
Cyndi's List is a large and comprehensive genealogical site, you will find most things here.
Egoshale Wills provides an exhaustive list
Malcolm McCarthy's list of Cornish Documents has interesting content.
1830 Piggots Directory for Wiltshire, Sue O'Neill is good enough to provide a copy of the Directory