for travel
www.thetube.com
day pass will cost around 5-6 pounds.
cheap hotels in london hmm will be hard to find, but stay away from few crapy ones in Paddington area.
holiday inn
ibis
or just try
www.lastminute.com,
www.londontown.com, and
http://www.visitlondon.co.uk/
are good sites for info. what can you u do is all according to your taste, visiting culture places, night clubs, restaurants etc. or shopping at oxford street and bond street.