Just some recommendations:
Get a London Travel Card here in the States. This allows you unlimited travel on the Tube(subway) - 7 days - $80.00
London Pass - 6 days - $89.00
London Tour Attractions:
Museums & Places of Interest
Historic Buildings
Tours Cruises Walks
Art Galleries
Restaurants, Cinemas, Theaters and more
Other Services and Savings
Depending on time / $$$ a day vist to Paris via The Chunnel.
www.visitlondon.com