Process
Strategic considerations will cause you to "bend" plans. E.g., some publication will forget to print what you sent, or give it poor positioning, some unexpected event or meeting may provide an opportunity for "sales".
Many kinds of activities will/should overlap. You can start "recruiting" before you've finished preparing all your publicity, and you can certainly gather names of potential walkers, donors, and volunteers from Day One.
But the earlier you have all printed and text materials generated, the easier it is. On the other hand, producing in smaller-than-expected batches allows you opportunities to modify and re-issue as becomes appropriate. Always carry some pieces of literature and some kind of sign-up cards with you.
Attend every meeting you can secure an invite to, and pitch each group for
- The group's "nominal" support
- The group's contribution of volunteer services (e.g. making phone calls--be prepared to supply lists of names and numbers)
- The individuals' direct support (as "sponsors" of yet-to-be-identified walkers, or as walkers).
Accept all offers! Then figure out how to use the resources provided.
As soon as any tasks are identified, try to think of people you know (they may be outsiders) who could whip that one up with one hand behind their back. Ask them to do it! Chances are, you'll get it done, and they'll say they "did nothing". Easy is good. Try not to saddle anyone with responsibilities they feel are heavy.
AND PRAY FOR SUN on walk day!