A long time ago an English friend told me about a town (not too far from London?) that had lots and lots and lots of bookshops. Is there such a place?
That would be Hay-on-Wye, in Wales. See http://www.hay-on-wye.com/
Wales is 150 miles from London.
Charing Cross Road in central London is the place for second hand books and home to Foyles (Largest book shop in the world)