Links:
English Monarchs
wonderful, informative site about all of the royal families of England and Scotland
British Titles and Order of Precedence
answers questions about which titles are above others, and how each is styled ie: Lord, Lady, etc.
Presidents and King John Plantagenet
interesting blog entry that refers to a study proving ancestral lines from all the U.S. presidents to King John Plantagenet
Historic UK/ Castles in England
alphabetical list of all the castles in England with descriptions and interactive map
Bodiam Castle, East Sussex, England