Nelly, check out
http://www.tfl.gov.uk/. it is a very useful site run by Transport for London. As Uxbridge and some of the other areas you mention are on the Underground you can find useful transportation information there.
Pinner and Northwood are very nice areas of Hillingdon and have their own Underground stations. However, to get to Uxbridge on the Underground you would have to change at Harrow. On the other hand, Ruislip is on the Uxbridge branch of the Metropolitan line so would be more direct. I've only been there once so can't really comment on the place apart from the fact that there are apparently a lot of US armed forces people there as I believe there is a base around there.
Watch out for the big restaurant by the station in Rickmansworth - worst restaurant in the UK! The most awful bland food. I think it has some lovingly, endearing name like Long Island Grill Restaurant (I hope the sarcasm comes through).
DTM - Reading is a town, not a city. What I want to know is, how does Milton Keynes get away with calling itself the New City of Milton Keynes? And does anyone believe it?
