http://www.viewlondon.co.uk/ is a good website. Did you know the Tour de France begins in London on the 7th/8th?
Also http://www.london-eating.co.uk/5970.htm C & R Cafe is fabulous. Does amazing Malaysian food and there is a set menu (for minimum of two people) which will comfortably feed at least three and is £16.95. They don’t have their own website but I know they are open every day including Sunday. But if you go on a Saturday then get there early cos I’ve seen people queuing for 30 minutes on a Saturday.