Don't beat yourself up, just start tracking again...You can do it!
I received the information today.  There isn't a specific WW walk, my book says to sign up for a 5K on June 6th, 2010.  The book is called Weigh Watchers Walk-it challenge, Your Step-by-Step Training Guide to Walking a 5K.  To find an Event go to weightwatchers.com/walkit (code:W25K66)  Or Google Search Find a 5 K in (your town)  
Or go to 
www.mapmywalk.com to plot out a 5K route.
Or find a public track in your area.  Most tracks are 400 meters 5 K is about 12 1/2 times around the track.
If you walk a 5K on Walk-it day you can receive a commemorative charm for your Weight Watchers Key ring.  I want to do it just to get one of those!  Good luck, I hope you got the book...if not go back and ask again.