Here is a wonderful example of a "get busy" page for campaigns. The directions are clear. There are lots of options. They point people to others resources, tools and events.
I also like the classes of supporters (On Your Ass, Part-Timer, Election Gorilla)
BTW: They have self-organized volunteers at more than 200 events nationally in the next 30 days. They are using a great tactical set of tools to support a strategy of distributed engagement.