Walking is not really a technique, but a style. One for which you need a good grasp of theory. Which you'll have better luck finding in General Instruction. Off you go, now.
FRANCIS&ELSIE, There are many existing threads on this subject, including this one: http://www.talkbass.com/forum/showthread.php?s=&threadid=21193&perpage=20&pagenumber=1 Try entering "walking bass" into the keyword search engine and seeing what's already been thrown out there. If you still need more info, everyone will still be here when you get back. Happy hunting! DURRL