"What do writers do when they're not writing? They walk."
Gertrude Stein

"If you want to know London better, if you want to learn some things about the world's most cosmopolitan city that most people who spend their lives there never learn. I can think of no better investment than London Walks"  
The New York Times

The Complete Jack the Ripper
by Donald Rumbelow

Jack the Ripper: Scotland Yard Investigates 
by Donald Rumbelow

A Literary Guide to London
by Ed Glinert

The London Compendium
by Ed Glinert

London's Dead 
by Ed Glinert

East End Chronicles
by Ed Glinert 

West End Chronicles
by Ed Glinert

Streets of the City
by Judy Pulley 

Exploring the Regent's Canal
by Michael Essex-Lopresti

Exploring the New River
by Michael Essex-Lopresti

The Green London Way
by Bob Gilbert

A Traveller's History of London
by Richard Tames

American Walks in London
by Richard Tames

City of London Past
by Richard Tames

Bloomsbury Past
by Richard Tames

Soho Past
by Richard Tames

Or pop into one of London's splendid bookshops - e.g.:

Waterstone's at Trafalgar Square
Waterstone's on Hampstead High Street
Hatchards at 187 Piccadilly
Waterstone's at 203-206 Piccadilly
Blackwell's at 100 Charing Crosss Road
Borders at 23-26 Piccadilly
Borders at 197-213 Oxford Street.