If you would like to go beyond the general walking guides here are a few suggestions 

Psychogeography by Will Self


A Field Guide to getting Lost by Rebecca Solnit Psychogeography by Merlin . This is a great introduction.

The Lost Art of Walking by Geoff Nicholson

The Natural Navigator by Tristan Gooley

DVDs made by Patrick Keeler such as London, Robinson in Space & Robinson in Ruins.