The Wordsworth Reference Library includes language dictionaries, language guides, historical references, and much more. This popular series covers everything from the familiar and practical to the extraordinary and outrageous.
A good introduction and overview of the history of the monarchy in England, with a little additional on monarchs in Wales, Scotland, and Ireland. A good basic resource.
The kings and queens of Britain range from dreadfully boring to unrealistically interesting. This will also probably be on my currently-reading list to infinity: I read it before going to bed because, in the worst cases, it dulls my mind and hurts my eyes, and in the best, I can't put it down (and it still puts me to sleep). But in any case, it'll be awhile.